Re: '88 YJ 258 ci with carter Hard Warm Start
 

Mike Romain <romainm@sympatico.ca> wrote in message news:<3F84C160.BEFBACD6@sympatico.ca>...
> Just a couple comments.
>
> A vapor or percolation lock will shut down a carb. If there isn't fuel
> pushing, the couple squirts you can get out of the accelerator pump
> won't start the engine. They just give a dry spark plug with a slight
> gas smell.
>
> And the ballast resistor is to give it 9 or so volts when running, the
> solenoid to coil tag gives battery power in a start, which is down below
> 12 usually with the starter sucking on it.
>
> It being still hot and dying is weird, but a shot of gas down the carb
> will tell all. Likely a rubber hose between the tank and frame or frame
> and engine has a crack, so sometimes it air locks fast, sometimes slow
> depending on the angle it stopped at.
>

Okay, shot down the carb did not work at all. Started small and
worked up to enough to soak the plugs. Didn't even try to start, not
even a little cough.

I rechecked the pumper pumps till dry bowl. After sitting for 3-4
hours with the fuel bowl vent hose off (I was still checking to see if
pressure building between the carbon canister and the carb was a
problem) it took 4 squirts to run it dry. I turned it over for 3
seconds to fill the bowl and tried the pumper again. 17 squirts to
dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
volume (~100 mL in 8 sec). That seemed pretty good to me.

So I start from the beginning again. It's never taken me so long to
get it started as yesterday. And Voila -- no spark at plug #1.
Rechecked my ground and wire snugness -- no spark A-ha! This I can
deal with. So I go through the ignition electronics troubleshooting
flowchart in the dealer service manual. With the key on the positive
terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
The next step is to disconnect the suppressor. Well that's long gone,
so I skip that step. Next is to pull loose the "I" wire from the
starter solenoid and check the coil positive terminal. My solenoid
doesn't look anything like the book's solenoid so I pull each wire off
in succession and check the voltage -- never goes to 6 V. Next is to
jumper the negative terminal of the coil to ground and check the
voltage -- AHA -- 6.0 volts. Check the continuity between the neg
terminal and ECM connector pin #42 -- continuity good. Next step --
replace the ECM. Major bummer. That's $180 bucks, says friendly
Advance Auto chick (I've got their number programmed into my cell
phone).

So, thanks for your advice and patience. You guys have been great.
Anybody have any ideas on how to do an off-vehicle verification that
my ECM is dead? I was going to just buy a new one and see if it fixed
the problem and return it if it didn't. But before I shell out $180
I'd like to verify it somehow.

Bob V.



> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> c wrote:
> >
> > <averyislandboy@yahoo.com> wrote in message
> > news:a188e6f3.0310081550.6c1b6b01@posting.google.c om...
> > > Mike Romain <romainm@sympatico.ca> wrote in message
> news:<3F83124C.E7063767@sympatico.ca>...
> > > > Jut try tossing a 1/8 cup or a couple tablespoons of gas down the carb
> > > > and see what happens.
> > > >
> > > > If it fires up, you have a hole in the gas line on the suction side of
> > > > the pump or a dead pump that is letting the gas backflow to the tank or
> > > > a torn diaphragm on the pump.
> > >
> > > The pump is brand new last month.
> > >
> > > >
> > > > Does the oil on the dipstick smell like gas?
> > >
> > > nope smells like SAE 30
> > >
> > > >
> > > > Oh, the choke is an electric timer job.
> > > >
> > > > It will be totally closed after 5 minutes and opens according to how
> > > > long 12 volts has been going to it. Piece of crap actually because it
> > > > doesn't have a clue how hot or cold the engine really is, just how long
> > > > it has had 12 volts.
> > >
> > > I don't think the choke is the prime offender since I tend to wedge it
> > > open while trying to start it.
> > >
> > > >
> > > > Mike
> > >
> > > Well, I actually took the plug wrench with me on a day that it acted
> > > up. Which was totally out of the normal pattern because it was cold
> > > and rainy. It also didn't start right up this morning, which is
> > > atypical. It started a couple of times throughout the day, but when
> > > it came to going home time it would not start. The engine was still
> > > warm from having driven to the office from our pilot plant in the
> > > previous 45 minutes or so. I cranked and cranked. Pumped the gas a
> > > couple of times for giggles and cranked. No start. Aha! I have the
> > > plug wrench, pulled out old number 1 and Voila, the plug, much to my
> > > surprise was not wet. I could catch a faint whiff of petro when I put
> > > it to my nose, but that's it. I don't think that that's classic
> > > textbook flooded car "wet". So much for my theories to date. Not
> > > having a remote starter (my wife wasn't at work with me, and the
> > > cleaning lady had already gone home) I couldn't check if I had spark.
> > > I scratched my head for a while, cranked it once with the plug hanging
> > > over the alternator (not that I could even begin to see it from the
> > > driver's seat. I didn't have a screwdriver to jump my solenoid, just
> > > a 1/2" wrench and my socket driver which seemed like a bad idea on a
> > > rainy day). So I put the plug back in, crank it and doggone it if it
> > > doesn't start. Huh? Thankful (especially to Mike for encouraging me
> > > to verify if it was flooded) and confused, I drive home brainstorming
> > > new theories.
> > >
> > > What about if I had "weak spark"? I have checked the coil resistances
> > > and it's good, but what if my starter and solenoid are getting "worn"
> > > and sucking more juice than they should, that could drop the system
> > > voltage pretty low and without 11-12V, would the coil work right? I'm
> > > thinking about putting my spare battery in the passenger floor and
> > > wiring it directly into the coil to ensure it is seeing 12V. Whacked
> > > idea? Other suggestions? Like I've described, once the thing is
> > > started it runs fine, but when it's running, the alternator is keeping
> > > the coil at a happy 12-13V.
> >
> > OK, I might have a couple ideas here based on all the things I've read in
> > this thread. First off, all of this is based on memory from what I've read,
> > so bear with me if I repeat something you've tried. I remember you saying
> > that when you pumped the accelerator after sitting, that the pump shot was
> > good for a couple shots and then it "went dry". This seems wrong to me. You
> > should get quite a few shots before the float bowl empties out. Definitely
> > more than 2 or 3. This leads me to believe that either the float level is
> > way too low, or possibly the fuel in the bowl is vaporizing from
> > percolation, or both. A carb has more tendency to percolate when the float
> > level is low because in essence the fuel cools the carburetor to some
> > extent. Fuel percolation can also cause both flooded conditions and no fuel
> > conditions, depending on how long the vehicle sits between starts. The fuel
> > can sometimes percolate until the bowl is empty. The percolation can cause
> > the fuel to siphon itself out of the carb through the fuel passages and into
> > the engine.
> >
> > Also, regarding the fuel pump, just because it is new doesn't mean it is
> > working properly. Try checking both volume and pressure. I'm not sure of the
> > volume specs for your pump, but most of them are usually about a pint in
> > 20-30 seconds of cranking. You'll have to check a service manual for your
> > specs. I believe the fuel pressure should be between 4-6 PSI. Like Mike
> > said, also check all of your fuel lines for pinholes. If the pump is sucking
> > air instead of fuel, this can also lead to the percolation condition. The
> > volume tests should reveal a suction problem as well.
> >
> > You may want to check the fuel you've been using. Maybe your gas station got
> > some bad gas, or possibly they have mixed in that reconstituted crap. Some
> > vehicles just flat won't run right on that stuff.
> >
> > As far as the spark being weak, I would say possible but not likely. Most
> > factory coils "amplify" the voltage by a factor of about 1600 or more, which
> > means that even with 8 volts going to the coil, you would have over 12000
> > volts going to the plugs. While this is not optimum, it will definitely fire
> > a plug enough to start the engine. Remember, a lot of the old point systems
> > had a ballast resistor in the ignition circuit to intentionally cut the
> > voltage back while cranking.
> >
> > Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

Mike Romain <romainm@sympatico.ca> wrote in message news:<3F84C160.BEFBACD6@sympatico.ca>...
> Just a couple comments.
>
> A vapor or percolation lock will shut down a carb. If there isn't fuel
> pushing, the couple squirts you can get out of the accelerator pump
> won't start the engine. They just give a dry spark plug with a slight
> gas smell.
>
> And the ballast resistor is to give it 9 or so volts when running, the
> solenoid to coil tag gives battery power in a start, which is down below
> 12 usually with the starter sucking on it.
>
> It being still hot and dying is weird, but a shot of gas down the carb
> will tell all. Likely a rubber hose between the tank and frame or frame
> and engine has a crack, so sometimes it air locks fast, sometimes slow
> depending on the angle it stopped at.
>

Okay, shot down the carb did not work at all. Started small and
worked up to enough to soak the plugs. Didn't even try to start, not
even a little cough.

I rechecked the pumper pumps till dry bowl. After sitting for 3-4
hours with the fuel bowl vent hose off (I was still checking to see if
pressure building between the carbon canister and the carb was a
problem) it took 4 squirts to run it dry. I turned it over for 3
seconds to fill the bowl and tried the pumper again. 17 squirts to
dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
volume (~100 mL in 8 sec). That seemed pretty good to me.

So I start from the beginning again. It's never taken me so long to
get it started as yesterday. And Voila -- no spark at plug #1.
Rechecked my ground and wire snugness -- no spark A-ha! This I can
deal with. So I go through the ignition electronics troubleshooting
flowchart in the dealer service manual. With the key on the positive
terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
The next step is to disconnect the suppressor. Well that's long gone,
so I skip that step. Next is to pull loose the "I" wire from the
starter solenoid and check the coil positive terminal. My solenoid
doesn't look anything like the book's solenoid so I pull each wire off
in succession and check the voltage -- never goes to 6 V. Next is to
jumper the negative terminal of the coil to ground and check the
voltage -- AHA -- 6.0 volts. Check the continuity between the neg
terminal and ECM connector pin #42 -- continuity good. Next step --
replace the ECM. Major bummer. That's $180 bucks, says friendly
Advance Auto chick (I've got their number programmed into my cell
phone).

So, thanks for your advice and patience. You guys have been great.
Anybody have any ideas on how to do an off-vehicle verification that
my ECM is dead? I was going to just buy a new one and see if it fixed
the problem and return it if it didn't. But before I shell out $180
I'd like to verify it somehow.

Bob V.



> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> c wrote:
> >
> > <averyislandboy@yahoo.com> wrote in message
> > news:a188e6f3.0310081550.6c1b6b01@posting.google.c om...
> > > Mike Romain <romainm@sympatico.ca> wrote in message
> news:<3F83124C.E7063767@sympatico.ca>...
> > > > Jut try tossing a 1/8 cup or a couple tablespoons of gas down the carb
> > > > and see what happens.
> > > >
> > > > If it fires up, you have a hole in the gas line on the suction side of
> > > > the pump or a dead pump that is letting the gas backflow to the tank or
> > > > a torn diaphragm on the pump.
> > >
> > > The pump is brand new last month.
> > >
> > > >
> > > > Does the oil on the dipstick smell like gas?
> > >
> > > nope smells like SAE 30
> > >
> > > >
> > > > Oh, the choke is an electric timer job.
> > > >
> > > > It will be totally closed after 5 minutes and opens according to how
> > > > long 12 volts has been going to it. Piece of crap actually because it
> > > > doesn't have a clue how hot or cold the engine really is, just how long
> > > > it has had 12 volts.
> > >
> > > I don't think the choke is the prime offender since I tend to wedge it
> > > open while trying to start it.
> > >
> > > >
> > > > Mike
> > >
> > > Well, I actually took the plug wrench with me on a day that it acted
> > > up. Which was totally out of the normal pattern because it was cold
> > > and rainy. It also didn't start right up this morning, which is
> > > atypical. It started a couple of times throughout the day, but when
> > > it came to going home time it would not start. The engine was still
> > > warm from having driven to the office from our pilot plant in the
> > > previous 45 minutes or so. I cranked and cranked. Pumped the gas a
> > > couple of times for giggles and cranked. No start. Aha! I have the
> > > plug wrench, pulled out old number 1 and Voila, the plug, much to my
> > > surprise was not wet. I could catch a faint whiff of petro when I put
> > > it to my nose, but that's it. I don't think that that's classic
> > > textbook flooded car "wet". So much for my theories to date. Not
> > > having a remote starter (my wife wasn't at work with me, and the
> > > cleaning lady had already gone home) I couldn't check if I had spark.
> > > I scratched my head for a while, cranked it once with the plug hanging
> > > over the alternator (not that I could even begin to see it from the
> > > driver's seat. I didn't have a screwdriver to jump my solenoid, just
> > > a 1/2" wrench and my socket driver which seemed like a bad idea on a
> > > rainy day). So I put the plug back in, crank it and doggone it if it
> > > doesn't start. Huh? Thankful (especially to Mike for encouraging me
> > > to verify if it was flooded) and confused, I drive home brainstorming
> > > new theories.
> > >
> > > What about if I had "weak spark"? I have checked the coil resistances
> > > and it's good, but what if my starter and solenoid are getting "worn"
> > > and sucking more juice than they should, that could drop the system
> > > voltage pretty low and without 11-12V, would the coil work right? I'm
> > > thinking about putting my spare battery in the passenger floor and
> > > wiring it directly into the coil to ensure it is seeing 12V. Whacked
> > > idea? Other suggestions? Like I've described, once the thing is
> > > started it runs fine, but when it's running, the alternator is keeping
> > > the coil at a happy 12-13V.
> >
> > OK, I might have a couple ideas here based on all the things I've read in
> > this thread. First off, all of this is based on memory from what I've read,
> > so bear with me if I repeat something you've tried. I remember you saying
> > that when you pumped the accelerator after sitting, that the pump shot was
> > good for a couple shots and then it "went dry". This seems wrong to me. You
> > should get quite a few shots before the float bowl empties out. Definitely
> > more than 2 or 3. This leads me to believe that either the float level is
> > way too low, or possibly the fuel in the bowl is vaporizing from
> > percolation, or both. A carb has more tendency to percolate when the float
> > level is low because in essence the fuel cools the carburetor to some
> > extent. Fuel percolation can also cause both flooded conditions and no fuel
> > conditions, depending on how long the vehicle sits between starts. The fuel
> > can sometimes percolate until the bowl is empty. The percolation can cause
> > the fuel to siphon itself out of the carb through the fuel passages and into
> > the engine.
> >
> > Also, regarding the fuel pump, just because it is new doesn't mean it is
> > working properly. Try checking both volume and pressure. I'm not sure of the
> > volume specs for your pump, but most of them are usually about a pint in
> > 20-30 seconds of cranking. You'll have to check a service manual for your
> > specs. I believe the fuel pressure should be between 4-6 PSI. Like Mike
> > said, also check all of your fuel lines for pinholes. If the pump is sucking
> > air instead of fuel, this can also lead to the percolation condition. The
> > volume tests should reveal a suction problem as well.
> >
> > You may want to check the fuel you've been using. Maybe your gas station got
> > some bad gas, or possibly they have mixed in that reconstituted crap. Some
> > vehicles just flat won't run right on that stuff.
> >
> > As far as the spark being weak, I would say possible but not likely. Most
> > factory coils "amplify" the voltage by a factor of about 1600 or more, which
> > means that even with 8 volts going to the coil, you would have over 12000
> > volts going to the plugs. While this is not optimum, it will definitely fire
> > a plug enough to start the engine. Remember, a lot of the old point systems
> > had a ballast resistor in the ignition circuit to intentionally cut the
> > voltage back while cranking.
> >
> > Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

Mike Romain <romainm@sympatico.ca> wrote in message news:<3F84C160.BEFBACD6@sympatico.ca>...
> Just a couple comments.
>
> A vapor or percolation lock will shut down a carb. If there isn't fuel
> pushing, the couple squirts you can get out of the accelerator pump
> won't start the engine. They just give a dry spark plug with a slight
> gas smell.
>
> And the ballast resistor is to give it 9 or so volts when running, the
> solenoid to coil tag gives battery power in a start, which is down below
> 12 usually with the starter sucking on it.
>
> It being still hot and dying is weird, but a shot of gas down the carb
> will tell all. Likely a rubber hose between the tank and frame or frame
> and engine has a crack, so sometimes it air locks fast, sometimes slow
> depending on the angle it stopped at.
>

Okay, shot down the carb did not work at all. Started small and
worked up to enough to soak the plugs. Didn't even try to start, not
even a little cough.

I rechecked the pumper pumps till dry bowl. After sitting for 3-4
hours with the fuel bowl vent hose off (I was still checking to see if
pressure building between the carbon canister and the carb was a
problem) it took 4 squirts to run it dry. I turned it over for 3
seconds to fill the bowl and tried the pumper again. 17 squirts to
dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
volume (~100 mL in 8 sec). That seemed pretty good to me.

So I start from the beginning again. It's never taken me so long to
get it started as yesterday. And Voila -- no spark at plug #1.
Rechecked my ground and wire snugness -- no spark A-ha! This I can
deal with. So I go through the ignition electronics troubleshooting
flowchart in the dealer service manual. With the key on the positive
terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
The next step is to disconnect the suppressor. Well that's long gone,
so I skip that step. Next is to pull loose the "I" wire from the
starter solenoid and check the coil positive terminal. My solenoid
doesn't look anything like the book's solenoid so I pull each wire off
in succession and check the voltage -- never goes to 6 V. Next is to
jumper the negative terminal of the coil to ground and check the
voltage -- AHA -- 6.0 volts. Check the continuity between the neg
terminal and ECM connector pin #42 -- continuity good. Next step --
replace the ECM. Major bummer. That's $180 bucks, says friendly
Advance Auto chick (I've got their number programmed into my cell
phone).

So, thanks for your advice and patience. You guys have been great.
Anybody have any ideas on how to do an off-vehicle verification that
my ECM is dead? I was going to just buy a new one and see if it fixed
the problem and return it if it didn't. But before I shell out $180
I'd like to verify it somehow.

Bob V.



> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> c wrote:
> >
> > <averyislandboy@yahoo.com> wrote in message
> > news:a188e6f3.0310081550.6c1b6b01@posting.google.c om...
> > > Mike Romain <romainm@sympatico.ca> wrote in message
> news:<3F83124C.E7063767@sympatico.ca>...
> > > > Jut try tossing a 1/8 cup or a couple tablespoons of gas down the carb
> > > > and see what happens.
> > > >
> > > > If it fires up, you have a hole in the gas line on the suction side of
> > > > the pump or a dead pump that is letting the gas backflow to the tank or
> > > > a torn diaphragm on the pump.
> > >
> > > The pump is brand new last month.
> > >
> > > >
> > > > Does the oil on the dipstick smell like gas?
> > >
> > > nope smells like SAE 30
> > >
> > > >
> > > > Oh, the choke is an electric timer job.
> > > >
> > > > It will be totally closed after 5 minutes and opens according to how
> > > > long 12 volts has been going to it. Piece of crap actually because it
> > > > doesn't have a clue how hot or cold the engine really is, just how long
> > > > it has had 12 volts.
> > >
> > > I don't think the choke is the prime offender since I tend to wedge it
> > > open while trying to start it.
> > >
> > > >
> > > > Mike
> > >
> > > Well, I actually took the plug wrench with me on a day that it acted
> > > up. Which was totally out of the normal pattern because it was cold
> > > and rainy. It also didn't start right up this morning, which is
> > > atypical. It started a couple of times throughout the day, but when
> > > it came to going home time it would not start. The engine was still
> > > warm from having driven to the office from our pilot plant in the
> > > previous 45 minutes or so. I cranked and cranked. Pumped the gas a
> > > couple of times for giggles and cranked. No start. Aha! I have the
> > > plug wrench, pulled out old number 1 and Voila, the plug, much to my
> > > surprise was not wet. I could catch a faint whiff of petro when I put
> > > it to my nose, but that's it. I don't think that that's classic
> > > textbook flooded car "wet". So much for my theories to date. Not
> > > having a remote starter (my wife wasn't at work with me, and the
> > > cleaning lady had already gone home) I couldn't check if I had spark.
> > > I scratched my head for a while, cranked it once with the plug hanging
> > > over the alternator (not that I could even begin to see it from the
> > > driver's seat. I didn't have a screwdriver to jump my solenoid, just
> > > a 1/2" wrench and my socket driver which seemed like a bad idea on a
> > > rainy day). So I put the plug back in, crank it and doggone it if it
> > > doesn't start. Huh? Thankful (especially to Mike for encouraging me
> > > to verify if it was flooded) and confused, I drive home brainstorming
> > > new theories.
> > >
> > > What about if I had "weak spark"? I have checked the coil resistances
> > > and it's good, but what if my starter and solenoid are getting "worn"
> > > and sucking more juice than they should, that could drop the system
> > > voltage pretty low and without 11-12V, would the coil work right? I'm
> > > thinking about putting my spare battery in the passenger floor and
> > > wiring it directly into the coil to ensure it is seeing 12V. Whacked
> > > idea? Other suggestions? Like I've described, once the thing is
> > > started it runs fine, but when it's running, the alternator is keeping
> > > the coil at a happy 12-13V.
> >
> > OK, I might have a couple ideas here based on all the things I've read in
> > this thread. First off, all of this is based on memory from what I've read,
> > so bear with me if I repeat something you've tried. I remember you saying
> > that when you pumped the accelerator after sitting, that the pump shot was
> > good for a couple shots and then it "went dry". This seems wrong to me. You
> > should get quite a few shots before the float bowl empties out. Definitely
> > more than 2 or 3. This leads me to believe that either the float level is
> > way too low, or possibly the fuel in the bowl is vaporizing from
> > percolation, or both. A carb has more tendency to percolate when the float
> > level is low because in essence the fuel cools the carburetor to some
> > extent. Fuel percolation can also cause both flooded conditions and no fuel
> > conditions, depending on how long the vehicle sits between starts. The fuel
> > can sometimes percolate until the bowl is empty. The percolation can cause
> > the fuel to siphon itself out of the carb through the fuel passages and into
> > the engine.
> >
> > Also, regarding the fuel pump, just because it is new doesn't mean it is
> > working properly. Try checking both volume and pressure. I'm not sure of the
> > volume specs for your pump, but most of them are usually about a pint in
> > 20-30 seconds of cranking. You'll have to check a service manual for your
> > specs. I believe the fuel pressure should be between 4-6 PSI. Like Mike
> > said, also check all of your fuel lines for pinholes. If the pump is sucking
> > air instead of fuel, this can also lead to the percolation condition. The
> > volume tests should reveal a suction problem as well.
> >
> > You may want to check the fuel you've been using. Maybe your gas station got
> > some bad gas, or possibly they have mixed in that reconstituted crap. Some
> > vehicles just flat won't run right on that stuff.
> >
> > As far as the spark being weak, I would say possible but not likely. Most
> > factory coils "amplify" the voltage by a factor of about 1600 or more, which
> > means that even with 8 volts going to the coil, you would have over 12000
> > volts going to the plugs. While this is not optimum, it will definitely fire
> > a plug enough to start the engine. Remember, a lot of the old point systems
> > had a ballast resistor in the ignition circuit to intentionally cut the
> > voltage back while cranking.
> >
> > Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

Interesting....

When you crank the starter can you see 9-12 volts at the coil positive?

With the key in run, you see 9 volts at the coil positive right? 6
volts is on the low side, most come in around 9.

If you don't see voltage at the coil positive with the starter turning
you likely have a solenoid or relay on the firewall by the battery
problem.

$180.00 for an ECM?????

Holy crap! They are only $70.00 or so up here in Canada.....

There is no way to test them. I keep a spare on hand for that purpose.

Mike

"averyislandboy@yahoo.com" wrote:
>
> Mike Romain <romainm@sympatico.ca> wrote in message news:<3F84C160.BEFBACD6@sympatico.ca>...
> > Just a couple comments.
> >
> > A vapor or percolation lock will shut down a carb. If there isn't fuel
> > pushing, the couple squirts you can get out of the accelerator pump
> > won't start the engine. They just give a dry spark plug with a slight
> > gas smell.
> >
> > And the ballast resistor is to give it 9 or so volts when running, the
> > solenoid to coil tag gives battery power in a start, which is down below
> > 12 usually with the starter sucking on it.
> >
> > It being still hot and dying is weird, but a shot of gas down the carb
> > will tell all. Likely a rubber hose between the tank and frame or frame
> > and engine has a crack, so sometimes it air locks fast, sometimes slow
> > depending on the angle it stopped at.
> >
>
> Okay, shot down the carb did not work at all. Started small and
> worked up to enough to soak the plugs. Didn't even try to start, not
> even a little cough.
>
> I rechecked the pumper pumps till dry bowl. After sitting for 3-4
> hours with the fuel bowl vent hose off (I was still checking to see if
> pressure building between the carbon canister and the carb was a
> problem) it took 4 squirts to run it dry. I turned it over for 3
> seconds to fill the bowl and tried the pumper again. 17 squirts to
> dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
> volume (~100 mL in 8 sec). That seemed pretty good to me.
>
> So I start from the beginning again. It's never taken me so long to
> get it started as yesterday. And Voila -- no spark at plug #1.
> Rechecked my ground and wire snugness -- no spark A-ha! This I can
> deal with. So I go through the ignition electronics troubleshooting
> flowchart in the dealer service manual. With the key on the positive
> terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
> The next step is to disconnect the suppressor. Well that's long gone,
> so I skip that step. Next is to pull loose the "I" wire from the
> starter solenoid and check the coil positive terminal. My solenoid
> doesn't look anything like the book's solenoid so I pull each wire off
> in succession and check the voltage -- never goes to 6 V. Next is to
> jumper the negative terminal of the coil to ground and check the
> voltage -- AHA -- 6.0 volts. Check the continuity between the neg
> terminal and ECM connector pin #42 -- continuity good. Next step --
> replace the ECM. Major bummer. That's $180 bucks, says friendly
> Advance Auto chick (I've got their number programmed into my cell
> phone).
>
> So, thanks for your advice and patience. You guys have been great.
> Anybody have any ideas on how to do an off-vehicle verification that
> my ECM is dead? I was going to just buy a new one and see if it fixed
> the problem and return it if it didn't. But before I shell out $180
> I'd like to verify it somehow.
>
> Bob V.
>
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > c wrote:
> > >
> > > <averyislandboy@yahoo.com> wrote in message
> > > news:a188e6f3.0310081550.6c1b6b01@posting.google.c om...
> > > > Mike Romain <romainm@sympatico.ca> wrote in message
> > news:<3F83124C.E7063767@sympatico.ca>...
> > > > > Jut try tossing a 1/8 cup or a couple tablespoons of gas down the carb
> > > > > and see what happens.
> > > > >
> > > > > If it fires up, you have a hole in the gas line on the suction side of
> > > > > the pump or a dead pump that is letting the gas backflow to the tank or
> > > > > a torn diaphragm on the pump.
> > > >
> > > > The pump is brand new last month.
> > > >
> > > > >
> > > > > Does the oil on the dipstick smell like gas?
> > > >
> > > > nope smells like SAE 30
> > > >
> > > > >
> > > > > Oh, the choke is an electric timer job.
> > > > >
> > > > > It will be totally closed after 5 minutes and opens according to how
> > > > > long 12 volts has been going to it. Piece of crap actually because it
> > > > > doesn't have a clue how hot or cold the engine really is, just how long
> > > > > it has had 12 volts.
> > > >
> > > > I don't think the choke is the prime offender since I tend to wedge it
> > > > open while trying to start it.
> > > >
> > > > >
> > > > > Mike
> > > >
> > > > Well, I actually took the plug wrench with me on a day that it acted
> > > > up. Which was totally out of the normal pattern because it was cold
> > > > and rainy. It also didn't start right up this morning, which is
> > > > atypical. It started a couple of times throughout the day, but when
> > > > it came to going home time it would not start. The engine was still
> > > > warm from having driven to the office from our pilot plant in the
> > > > previous 45 minutes or so. I cranked and cranked. Pumped the gas a
> > > > couple of times for giggles and cranked. No start. Aha! I have the
> > > > plug wrench, pulled out old number 1 and Voila, the plug, much to my
> > > > surprise was not wet. I could catch a faint whiff of petro when I put
> > > > it to my nose, but that's it. I don't think that that's classic
> > > > textbook flooded car "wet". So much for my theories to date. Not
> > > > having a remote starter (my wife wasn't at work with me, and the
> > > > cleaning lady had already gone home) I couldn't check if I had spark.
> > > > I scratched my head for a while, cranked it once with the plug hanging
> > > > over the alternator (not that I could even begin to see it from the
> > > > driver's seat. I didn't have a screwdriver to jump my solenoid, just
> > > > a 1/2" wrench and my socket driver which seemed like a bad idea on a
> > > > rainy day). So I put the plug back in, crank it and doggone it if it
> > > > doesn't start. Huh? Thankful (especially to Mike for encouraging me
> > > > to verify if it was flooded) and confused, I drive home brainstorming
> > > > new theories.
> > > >
> > > > What about if I had "weak spark"? I have checked the coil resistances
> > > > and it's good, but what if my starter and solenoid are getting "worn"
> > > > and sucking more juice than they should, that could drop the system
> > > > voltage pretty low and without 11-12V, would the coil work right? I'm
> > > > thinking about putting my spare battery in the passenger floor and
> > > > wiring it directly into the coil to ensure it is seeing 12V. Whacked
> > > > idea? Other suggestions? Like I've described, once the thing is
> > > > started it runs fine, but when it's running, the alternator is keeping
> > > > the coil at a happy 12-13V.
> > >
> > > OK, I might have a couple ideas here based on all the things I've read in
> > > this thread. First off, all of this is based on memory from what I've read,
> > > so bear with me if I repeat something you've tried. I remember you saying
> > > that when you pumped the accelerator after sitting, that the pump shot was
> > > good for a couple shots and then it "went dry". This seems wrong to me. You
> > > should get quite a few shots before the float bowl empties out. Definitely
> > > more than 2 or 3. This leads me to believe that either the float level is
> > > way too low, or possibly the fuel in the bowl is vaporizing from
> > > percolation, or both. A carb has more tendency to percolate when the float
> > > level is low because in essence the fuel cools the carburetor to some
> > > extent. Fuel percolation can also cause both flooded conditions and no fuel
> > > conditions, depending on how long the vehicle sits between starts. The fuel
> > > can sometimes percolate until the bowl is empty. The percolation can cause
> > > the fuel to siphon itself out of the carb through the fuel passages and into
> > > the engine.
> > >
> > > Also, regarding the fuel pump, just because it is new doesn't mean it is
> > > working properly. Try checking both volume and pressure. I'm not sure of the
> > > volume specs for your pump, but most of them are usually about a pint in
> > > 20-30 seconds of cranking. You'll have to check a service manual for your
> > > specs. I believe the fuel pressure should be between 4-6 PSI. Like Mike
> > > said, also check all of your fuel lines for pinholes. If the pump is sucking
> > > air instead of fuel, this can also lead to the percolation condition. The
> > > volume tests should reveal a suction problem as well.
> > >
> > > You may want to check the fuel you've been using. Maybe your gas station got
> > > some bad gas, or possibly they have mixed in that reconstituted crap. Some
> > > vehicles just flat won't run right on that stuff.
> > >
> > > As far as the spark being weak, I would say possible but not likely. Most
> > > factory coils "amplify" the voltage by a factor of about 1600 or more, which
> > > means that even with 8 volts going to the coil, you would have over 12000
> > > volts going to the plugs. While this is not optimum, it will definitely fire
> > > a plug enough to start the engine. Remember, a lot of the old point systems
> > > had a ballast resistor in the ignition circuit to intentionally cut the
> > > voltage back while cranking.
> > >
> > > Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

Interesting....

When you crank the starter can you see 9-12 volts at the coil positive?

With the key in run, you see 9 volts at the coil positive right? 6
volts is on the low side, most come in around 9.

If you don't see voltage at the coil positive with the starter turning
you likely have a solenoid or relay on the firewall by the battery
problem.

$180.00 for an ECM?????

Holy crap! They are only $70.00 or so up here in Canada.....

There is no way to test them. I keep a spare on hand for that purpose.

Mike

"averyislandboy@yahoo.com" wrote:
>
> Mike Romain <romainm@sympatico.ca> wrote in message news:<3F84C160.BEFBACD6@sympatico.ca>...
> > Just a couple comments.
> >
> > A vapor or percolation lock will shut down a carb. If there isn't fuel
> > pushing, the couple squirts you can get out of the accelerator pump
> > won't start the engine. They just give a dry spark plug with a slight
> > gas smell.
> >
> > And the ballast resistor is to give it 9 or so volts when running, the
> > solenoid to coil tag gives battery power in a start, which is down below
> > 12 usually with the starter sucking on it.
> >
> > It being still hot and dying is weird, but a shot of gas down the carb
> > will tell all. Likely a rubber hose between the tank and frame or frame
> > and engine has a crack, so sometimes it air locks fast, sometimes slow
> > depending on the angle it stopped at.
> >
>
> Okay, shot down the carb did not work at all. Started small and
> worked up to enough to soak the plugs. Didn't even try to start, not
> even a little cough.
>
> I rechecked the pumper pumps till dry bowl. After sitting for 3-4
> hours with the fuel bowl vent hose off (I was still checking to see if
> pressure building between the carbon canister and the carb was a
> problem) it took 4 squirts to run it dry. I turned it over for 3
> seconds to fill the bowl and tried the pumper again. 17 squirts to
> dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
> volume (~100 mL in 8 sec). That seemed pretty good to me.
>
> So I start from the beginning again. It's never taken me so long to
> get it started as yesterday. And Voila -- no spark at plug #1.
> Rechecked my ground and wire snugness -- no spark A-ha! This I can
> deal with. So I go through the ignition electronics troubleshooting
> flowchart in the dealer service manual. With the key on the positive
> terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
> The next step is to disconnect the suppressor. Well that's long gone,
> so I skip that step. Next is to pull loose the "I" wire from the
> starter solenoid and check the coil positive terminal. My solenoid
> doesn't look anything like the book's solenoid so I pull each wire off
> in succession and check the voltage -- never goes to 6 V. Next is to
> jumper the negative terminal of the coil to ground and check the
> voltage -- AHA -- 6.0 volts. Check the continuity between the neg
> terminal and ECM connector pin #42 -- continuity good. Next step --
> replace the ECM. Major bummer. That's $180 bucks, says friendly
> Advance Auto chick (I've got their number programmed into my cell
> phone).
>
> So, thanks for your advice and patience. You guys have been great.
> Anybody have any ideas on how to do an off-vehicle verification that
> my ECM is dead? I was going to just buy a new one and see if it fixed
> the problem and return it if it didn't. But before I shell out $180
> I'd like to verify it somehow.
>
> Bob V.
>
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > c wrote:
> > >
> > > <averyislandboy@yahoo.com> wrote in message
> > > news:a188e6f3.0310081550.6c1b6b01@posting.google.c om...
> > > > Mike Romain <romainm@sympatico.ca> wrote in message
> > news:<3F83124C.E7063767@sympatico.ca>...
> > > > > Jut try tossing a 1/8 cup or a couple tablespoons of gas down the carb
> > > > > and see what happens.
> > > > >
> > > > > If it fires up, you have a hole in the gas line on the suction side of
> > > > > the pump or a dead pump that is letting the gas backflow to the tank or
> > > > > a torn diaphragm on the pump.
> > > >
> > > > The pump is brand new last month.
> > > >
> > > > >
> > > > > Does the oil on the dipstick smell like gas?
> > > >
> > > > nope smells like SAE 30
> > > >
> > > > >
> > > > > Oh, the choke is an electric timer job.
> > > > >
> > > > > It will be totally closed after 5 minutes and opens according to how
> > > > > long 12 volts has been going to it. Piece of crap actually because it
> > > > > doesn't have a clue how hot or cold the engine really is, just how long
> > > > > it has had 12 volts.
> > > >
> > > > I don't think the choke is the prime offender since I tend to wedge it
> > > > open while trying to start it.
> > > >
> > > > >
> > > > > Mike
> > > >
> > > > Well, I actually took the plug wrench with me on a day that it acted
> > > > up. Which was totally out of the normal pattern because it was cold
> > > > and rainy. It also didn't start right up this morning, which is
> > > > atypical. It started a couple of times throughout the day, but when
> > > > it came to going home time it would not start. The engine was still
> > > > warm from having driven to the office from our pilot plant in the
> > > > previous 45 minutes or so. I cranked and cranked. Pumped the gas a
> > > > couple of times for giggles and cranked. No start. Aha! I have the
> > > > plug wrench, pulled out old number 1 and Voila, the plug, much to my
> > > > surprise was not wet. I could catch a faint whiff of petro when I put
> > > > it to my nose, but that's it. I don't think that that's classic
> > > > textbook flooded car "wet". So much for my theories to date. Not
> > > > having a remote starter (my wife wasn't at work with me, and the
> > > > cleaning lady had already gone home) I couldn't check if I had spark.
> > > > I scratched my head for a while, cranked it once with the plug hanging
> > > > over the alternator (not that I could even begin to see it from the
> > > > driver's seat. I didn't have a screwdriver to jump my solenoid, just
> > > > a 1/2" wrench and my socket driver which seemed like a bad idea on a
> > > > rainy day). So I put the plug back in, crank it and doggone it if it
> > > > doesn't start. Huh? Thankful (especially to Mike for encouraging me
> > > > to verify if it was flooded) and confused, I drive home brainstorming
> > > > new theories.
> > > >
> > > > What about if I had "weak spark"? I have checked the coil resistances
> > > > and it's good, but what if my starter and solenoid are getting "worn"
> > > > and sucking more juice than they should, that could drop the system
> > > > voltage pretty low and without 11-12V, would the coil work right? I'm
> > > > thinking about putting my spare battery in the passenger floor and
> > > > wiring it directly into the coil to ensure it is seeing 12V. Whacked
> > > > idea? Other suggestions? Like I've described, once the thing is
> > > > started it runs fine, but when it's running, the alternator is keeping
> > > > the coil at a happy 12-13V.
> > >
> > > OK, I might have a couple ideas here based on all the things I've read in
> > > this thread. First off, all of this is based on memory from what I've read,
> > > so bear with me if I repeat something you've tried. I remember you saying
> > > that when you pumped the accelerator after sitting, that the pump shot was
> > > good for a couple shots and then it "went dry". This seems wrong to me. You
> > > should get quite a few shots before the float bowl empties out. Definitely
> > > more than 2 or 3. This leads me to believe that either the float level is
> > > way too low, or possibly the fuel in the bowl is vaporizing from
> > > percolation, or both. A carb has more tendency to percolate when the float
> > > level is low because in essence the fuel cools the carburetor to some
> > > extent. Fuel percolation can also cause both flooded conditions and no fuel
> > > conditions, depending on how long the vehicle sits between starts. The fuel
> > > can sometimes percolate until the bowl is empty. The percolation can cause
> > > the fuel to siphon itself out of the carb through the fuel passages and into
> > > the engine.
> > >
> > > Also, regarding the fuel pump, just because it is new doesn't mean it is
> > > working properly. Try checking both volume and pressure. I'm not sure of the
> > > volume specs for your pump, but most of them are usually about a pint in
> > > 20-30 seconds of cranking. You'll have to check a service manual for your
> > > specs. I believe the fuel pressure should be between 4-6 PSI. Like Mike
> > > said, also check all of your fuel lines for pinholes. If the pump is sucking
> > > air instead of fuel, this can also lead to the percolation condition. The
> > > volume tests should reveal a suction problem as well.
> > >
> > > You may want to check the fuel you've been using. Maybe your gas station got
> > > some bad gas, or possibly they have mixed in that reconstituted crap. Some
> > > vehicles just flat won't run right on that stuff.
> > >
> > > As far as the spark being weak, I would say possible but not likely. Most
> > > factory coils "amplify" the voltage by a factor of about 1600 or more, which
> > > means that even with 8 volts going to the coil, you would have over 12000
> > > volts going to the plugs. While this is not optimum, it will definitely fire
> > > a plug enough to start the engine. Remember, a lot of the old point systems
> > > had a ballast resistor in the ignition circuit to intentionally cut the
> > > voltage back while cranking.
> > >
> > > Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

Interesting....

When you crank the starter can you see 9-12 volts at the coil positive?

With the key in run, you see 9 volts at the coil positive right? 6
volts is on the low side, most come in around 9.

If you don't see voltage at the coil positive with the starter turning
you likely have a solenoid or relay on the firewall by the battery
problem.

$180.00 for an ECM?????

Holy crap! They are only $70.00 or so up here in Canada.....

There is no way to test them. I keep a spare on hand for that purpose.

Mike

"averyislandboy@yahoo.com" wrote:
>
> Mike Romain <romainm@sympatico.ca> wrote in message news:<3F84C160.BEFBACD6@sympatico.ca>...
> > Just a couple comments.
> >
> > A vapor or percolation lock will shut down a carb. If there isn't fuel
> > pushing, the couple squirts you can get out of the accelerator pump
> > won't start the engine. They just give a dry spark plug with a slight
> > gas smell.
> >
> > And the ballast resistor is to give it 9 or so volts when running, the
> > solenoid to coil tag gives battery power in a start, which is down below
> > 12 usually with the starter sucking on it.
> >
> > It being still hot and dying is weird, but a shot of gas down the carb
> > will tell all. Likely a rubber hose between the tank and frame or frame
> > and engine has a crack, so sometimes it air locks fast, sometimes slow
> > depending on the angle it stopped at.
> >
>
> Okay, shot down the carb did not work at all. Started small and
> worked up to enough to soak the plugs. Didn't even try to start, not
> even a little cough.
>
> I rechecked the pumper pumps till dry bowl. After sitting for 3-4
> hours with the fuel bowl vent hose off (I was still checking to see if
> pressure building between the carbon canister and the carb was a
> problem) it took 4 squirts to run it dry. I turned it over for 3
> seconds to fill the bowl and tried the pumper again. 17 squirts to
> dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
> volume (~100 mL in 8 sec). That seemed pretty good to me.
>
> So I start from the beginning again. It's never taken me so long to
> get it started as yesterday. And Voila -- no spark at plug #1.
> Rechecked my ground and wire snugness -- no spark A-ha! This I can
> deal with. So I go through the ignition electronics troubleshooting
> flowchart in the dealer service manual. With the key on the positive
> terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
> The next step is to disconnect the suppressor. Well that's long gone,
> so I skip that step. Next is to pull loose the "I" wire from the
> starter solenoid and check the coil positive terminal. My solenoid
> doesn't look anything like the book's solenoid so I pull each wire off
> in succession and check the voltage -- never goes to 6 V. Next is to
> jumper the negative terminal of the coil to ground and check the
> voltage -- AHA -- 6.0 volts. Check the continuity between the neg
> terminal and ECM connector pin #42 -- continuity good. Next step --
> replace the ECM. Major bummer. That's $180 bucks, says friendly
> Advance Auto chick (I've got their number programmed into my cell
> phone).
>
> So, thanks for your advice and patience. You guys have been great.
> Anybody have any ideas on how to do an off-vehicle verification that
> my ECM is dead? I was going to just buy a new one and see if it fixed
> the problem and return it if it didn't. But before I shell out $180
> I'd like to verify it somehow.
>
> Bob V.
>
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > c wrote:
> > >
> > > <averyislandboy@yahoo.com> wrote in message
> > > news:a188e6f3.0310081550.6c1b6b01@posting.google.c om...
> > > > Mike Romain <romainm@sympatico.ca> wrote in message
> > news:<3F83124C.E7063767@sympatico.ca>...
> > > > > Jut try tossing a 1/8 cup or a couple tablespoons of gas down the carb
> > > > > and see what happens.
> > > > >
> > > > > If it fires up, you have a hole in the gas line on the suction side of
> > > > > the pump or a dead pump that is letting the gas backflow to the tank or
> > > > > a torn diaphragm on the pump.
> > > >
> > > > The pump is brand new last month.
> > > >
> > > > >
> > > > > Does the oil on the dipstick smell like gas?
> > > >
> > > > nope smells like SAE 30
> > > >
> > > > >
> > > > > Oh, the choke is an electric timer job.
> > > > >
> > > > > It will be totally closed after 5 minutes and opens according to how
> > > > > long 12 volts has been going to it. Piece of crap actually because it
> > > > > doesn't have a clue how hot or cold the engine really is, just how long
> > > > > it has had 12 volts.
> > > >
> > > > I don't think the choke is the prime offender since I tend to wedge it
> > > > open while trying to start it.
> > > >
> > > > >
> > > > > Mike
> > > >
> > > > Well, I actually took the plug wrench with me on a day that it acted
> > > > up. Which was totally out of the normal pattern because it was cold
> > > > and rainy. It also didn't start right up this morning, which is
> > > > atypical. It started a couple of times throughout the day, but when
> > > > it came to going home time it would not start. The engine was still
> > > > warm from having driven to the office from our pilot plant in the
> > > > previous 45 minutes or so. I cranked and cranked. Pumped the gas a
> > > > couple of times for giggles and cranked. No start. Aha! I have the
> > > > plug wrench, pulled out old number 1 and Voila, the plug, much to my
> > > > surprise was not wet. I could catch a faint whiff of petro when I put
> > > > it to my nose, but that's it. I don't think that that's classic
> > > > textbook flooded car "wet". So much for my theories to date. Not
> > > > having a remote starter (my wife wasn't at work with me, and the
> > > > cleaning lady had already gone home) I couldn't check if I had spark.
> > > > I scratched my head for a while, cranked it once with the plug hanging
> > > > over the alternator (not that I could even begin to see it from the
> > > > driver's seat. I didn't have a screwdriver to jump my solenoid, just
> > > > a 1/2" wrench and my socket driver which seemed like a bad idea on a
> > > > rainy day). So I put the plug back in, crank it and doggone it if it
> > > > doesn't start. Huh? Thankful (especially to Mike for encouraging me
> > > > to verify if it was flooded) and confused, I drive home brainstorming
> > > > new theories.
> > > >
> > > > What about if I had "weak spark"? I have checked the coil resistances
> > > > and it's good, but what if my starter and solenoid are getting "worn"
> > > > and sucking more juice than they should, that could drop the system
> > > > voltage pretty low and without 11-12V, would the coil work right? I'm
> > > > thinking about putting my spare battery in the passenger floor and
> > > > wiring it directly into the coil to ensure it is seeing 12V. Whacked
> > > > idea? Other suggestions? Like I've described, once the thing is
> > > > started it runs fine, but when it's running, the alternator is keeping
> > > > the coil at a happy 12-13V.
> > >
> > > OK, I might have a couple ideas here based on all the things I've read in
> > > this thread. First off, all of this is based on memory from what I've read,
> > > so bear with me if I repeat something you've tried. I remember you saying
> > > that when you pumped the accelerator after sitting, that the pump shot was
> > > good for a couple shots and then it "went dry". This seems wrong to me. You
> > > should get quite a few shots before the float bowl empties out. Definitely
> > > more than 2 or 3. This leads me to believe that either the float level is
> > > way too low, or possibly the fuel in the bowl is vaporizing from
> > > percolation, or both. A carb has more tendency to percolate when the float
> > > level is low because in essence the fuel cools the carburetor to some
> > > extent. Fuel percolation can also cause both flooded conditions and no fuel
> > > conditions, depending on how long the vehicle sits between starts. The fuel
> > > can sometimes percolate until the bowl is empty. The percolation can cause
> > > the fuel to siphon itself out of the carb through the fuel passages and into
> > > the engine.
> > >
> > > Also, regarding the fuel pump, just because it is new doesn't mean it is
> > > working properly. Try checking both volume and pressure. I'm not sure of the
> > > volume specs for your pump, but most of them are usually about a pint in
> > > 20-30 seconds of cranking. You'll have to check a service manual for your
> > > specs. I believe the fuel pressure should be between 4-6 PSI. Like Mike
> > > said, also check all of your fuel lines for pinholes. If the pump is sucking
> > > air instead of fuel, this can also lead to the percolation condition. The
> > > volume tests should reveal a suction problem as well.
> > >
> > > You may want to check the fuel you've been using. Maybe your gas station got
> > > some bad gas, or possibly they have mixed in that reconstituted crap. Some
> > > vehicles just flat won't run right on that stuff.
> > >
> > > As far as the spark being weak, I would say possible but not likely. Most
> > > factory coils "amplify" the voltage by a factor of about 1600 or more, which
> > > means that even with 8 volts going to the coil, you would have over 12000
> > > volts going to the plugs. While this is not optimum, it will definitely fire
> > > a plug enough to start the engine. Remember, a lot of the old point systems
> > > had a ballast resistor in the ignition circuit to intentionally cut the
> > > voltage back while cranking.
> > >
> > > Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

averyislandboy@yahoo.com wrote:
> Mike Romain <romainm@sympatico.ca> wrote in message
> news:<3F84C160.BEFBACD6@sympatico.ca>...
>> Just a couple comments.
>>
>> A vapor or percolation lock will shut down a carb. If there isn't
>> fuel pushing, the couple squirts you can get out of the accelerator
>> pump won't start the engine. They just give a dry spark plug with a
>> slight gas smell.
>>
>> And the ballast resistor is to give it 9 or so volts when running,
>> the solenoid to coil tag gives battery power in a start, which is
>> down below 12 usually with the starter sucking on it.
>>
>> It being still hot and dying is weird, but a shot of gas down the
>> carb will tell all. Likely a rubber hose between the tank and frame
>> or frame and engine has a crack, so sometimes it air locks fast,
>> sometimes slow depending on the angle it stopped at.
>>
>
> Okay, shot down the carb did not work at all. Started small and
> worked up to enough to soak the plugs. Didn't even try to start, not
> even a little cough.
>
> I rechecked the pumper pumps till dry bowl. After sitting for 3-4
> hours with the fuel bowl vent hose off (I was still checking to see if
> pressure building between the carbon canister and the carb was a
> problem) it took 4 squirts to run it dry. I turned it over for 3
> seconds to fill the bowl and tried the pumper again. 17 squirts to
> dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
> volume (~100 mL in 8 sec). That seemed pretty good to me.
>
> So I start from the beginning again. It's never taken me so long to
> get it started as yesterday. And Voila -- no spark at plug #1.
> Rechecked my ground and wire snugness -- no spark A-ha! This I can
> deal with. So I go through the ignition electronics troubleshooting
> flowchart in the dealer service manual. With the key on the positive
> terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
> The next step is to disconnect the suppressor. Well that's long gone,
> so I skip that step. Next is to pull loose the "I" wire from the
> starter solenoid and check the coil positive terminal. My solenoid
> doesn't look anything like the book's solenoid so I pull each wire off
> in succession and check the voltage -- never goes to 6 V. Next is to
> jumper the negative terminal of the coil to ground and check the
> voltage -- AHA -- 6.0 volts. Check the continuity between the neg
> terminal and ECM connector pin #42 -- continuity good. Next step --
> replace the ECM. Major bummer. That's $180 bucks, says friendly
> Advance Auto chick (I've got their number programmed into my cell
> phone).
>
> So, thanks for your advice and patience. You guys have been great.
> Anybody have any ideas on how to do an off-vehicle verification that
> my ECM is dead? I was going to just buy a new one and see if it fixed
> the problem and return it if it didn't. But before I shell out $180
> I'd like to verify it somehow.
>
> Bob V.
>
>
Be careful with the plan of returning an ECM. Most part stores won't take
returns on electrical gismos. However, most ECMs can be tested with either a
special tester, or a multimeter. Not sure on yours, but Mike probably knows.

Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

averyislandboy@yahoo.com wrote:
> Mike Romain <romainm@sympatico.ca> wrote in message
> news:<3F84C160.BEFBACD6@sympatico.ca>...
>> Just a couple comments.
>>
>> A vapor or percolation lock will shut down a carb. If there isn't
>> fuel pushing, the couple squirts you can get out of the accelerator
>> pump won't start the engine. They just give a dry spark plug with a
>> slight gas smell.
>>
>> And the ballast resistor is to give it 9 or so volts when running,
>> the solenoid to coil tag gives battery power in a start, which is
>> down below 12 usually with the starter sucking on it.
>>
>> It being still hot and dying is weird, but a shot of gas down the
>> carb will tell all. Likely a rubber hose between the tank and frame
>> or frame and engine has a crack, so sometimes it air locks fast,
>> sometimes slow depending on the angle it stopped at.
>>
>
> Okay, shot down the carb did not work at all. Started small and
> worked up to enough to soak the plugs. Didn't even try to start, not
> even a little cough.
>
> I rechecked the pumper pumps till dry bowl. After sitting for 3-4
> hours with the fuel bowl vent hose off (I was still checking to see if
> pressure building between the carbon canister and the carb was a
> problem) it took 4 squirts to run it dry. I turned it over for 3
> seconds to fill the bowl and tried the pumper again. 17 squirts to
> dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
> volume (~100 mL in 8 sec). That seemed pretty good to me.
>
> So I start from the beginning again. It's never taken me so long to
> get it started as yesterday. And Voila -- no spark at plug #1.
> Rechecked my ground and wire snugness -- no spark A-ha! This I can
> deal with. So I go through the ignition electronics troubleshooting
> flowchart in the dealer service manual. With the key on the positive
> terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
> The next step is to disconnect the suppressor. Well that's long gone,
> so I skip that step. Next is to pull loose the "I" wire from the
> starter solenoid and check the coil positive terminal. My solenoid
> doesn't look anything like the book's solenoid so I pull each wire off
> in succession and check the voltage -- never goes to 6 V. Next is to
> jumper the negative terminal of the coil to ground and check the
> voltage -- AHA -- 6.0 volts. Check the continuity between the neg
> terminal and ECM connector pin #42 -- continuity good. Next step --
> replace the ECM. Major bummer. That's $180 bucks, says friendly
> Advance Auto chick (I've got their number programmed into my cell
> phone).
>
> So, thanks for your advice and patience. You guys have been great.
> Anybody have any ideas on how to do an off-vehicle verification that
> my ECM is dead? I was going to just buy a new one and see if it fixed
> the problem and return it if it didn't. But before I shell out $180
> I'd like to verify it somehow.
>
> Bob V.
>
>
Be careful with the plan of returning an ECM. Most part stores won't take
returns on electrical gismos. However, most ECMs can be tested with either a
special tester, or a multimeter. Not sure on yours, but Mike probably knows.

Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

averyislandboy@yahoo.com wrote:
> Mike Romain <romainm@sympatico.ca> wrote in message
> news:<3F84C160.BEFBACD6@sympatico.ca>...
>> Just a couple comments.
>>
>> A vapor or percolation lock will shut down a carb. If there isn't
>> fuel pushing, the couple squirts you can get out of the accelerator
>> pump won't start the engine. They just give a dry spark plug with a
>> slight gas smell.
>>
>> And the ballast resistor is to give it 9 or so volts when running,
>> the solenoid to coil tag gives battery power in a start, which is
>> down below 12 usually with the starter sucking on it.
>>
>> It being still hot and dying is weird, but a shot of gas down the
>> carb will tell all. Likely a rubber hose between the tank and frame
>> or frame and engine has a crack, so sometimes it air locks fast,
>> sometimes slow depending on the angle it stopped at.
>>
>
> Okay, shot down the carb did not work at all. Started small and
> worked up to enough to soak the plugs. Didn't even try to start, not
> even a little cough.
>
> I rechecked the pumper pumps till dry bowl. After sitting for 3-4
> hours with the fuel bowl vent hose off (I was still checking to see if
> pressure building between the carbon canister and the carb was a
> problem) it took 4 squirts to run it dry. I turned it over for 3
> seconds to fill the bowl and tried the pumper again. 17 squirts to
> dry bowl. Again, 17 squirts. I verified the pressure (6 psi) and the
> volume (~100 mL in 8 sec). That seemed pretty good to me.
>
> So I start from the beginning again. It's never taken me so long to
> get it started as yesterday. And Voila -- no spark at plug #1.
> Rechecked my ground and wire snugness -- no spark A-ha! This I can
> deal with. So I go through the ignition electronics troubleshooting
> flowchart in the dealer service manual. With the key on the positive
> terminal at the coil should be 6V +/- 0.5V. Well it's reading 9 V.
> The next step is to disconnect the suppressor. Well that's long gone,
> so I skip that step. Next is to pull loose the "I" wire from the
> starter solenoid and check the coil positive terminal. My solenoid
> doesn't look anything like the book's solenoid so I pull each wire off
> in succession and check the voltage -- never goes to 6 V. Next is to
> jumper the negative terminal of the coil to ground and check the
> voltage -- AHA -- 6.0 volts. Check the continuity between the neg
> terminal and ECM connector pin #42 -- continuity good. Next step --
> replace the ECM. Major bummer. That's $180 bucks, says friendly
> Advance Auto chick (I've got their number programmed into my cell
> phone).
>
> So, thanks for your advice and patience. You guys have been great.
> Anybody have any ideas on how to do an off-vehicle verification that
> my ECM is dead? I was going to just buy a new one and see if it fixed
> the problem and return it if it didn't. But before I shell out $180
> I'd like to verify it somehow.
>
> Bob V.
>
>
Be careful with the plan of returning an ECM. Most part stores won't take
returns on electrical gismos. However, most ECMs can be tested with either a
special tester, or a multimeter. Not sure on yours, but Mike probably knows.

Chris

Re: '88 YJ 258 ci with carter Hard Warm Start
 

<averyislandboy@yahoo.com> wrote in message
news:a188e6f3.0310101115.573f91e9@posting.google.c om...
....
> The next step is to disconnect the suppressor. Well that's long gone,
> so I skip that step.

You must like blowing up modules... that supressor is not
there just for good looks.
__
Steve
..