Mike Romain

That is perfect.

You have no power to the coil issues.

The power comes through a ballast wire that acts like a voltage
regulator sort of. It lowers the voltage.

The pulsing is because the negative on the coil pulses from the
distributor pickup to send the spark to one cylinder at a time by
shutting off the coil.

Mike

pomerom@yahoo.com wrote:
>
> Took your advice and checked some voltages.
>
> Battery (all measured with a multimeter across the battery terminals):
> 1: Prior to starting = 13.2
> 2: While starter engaged = 11
> 3: While running at a very fast idle = 14.5-14.6
>
> Voltage to coil (measured with a multimeter from the negative battery
> terminal to the red wire on top of the coil itself):
> 1: With engine off but key on = 7.6
> 2: With engine running at a fast (though ragged missing) idle = 10.9-
> 11.2
>
> And, note, this 10.9-11.2 was bouncing around constantly, not staying
> steady at all.
>
> Make any sense? Provide any clues??
>
> Mike
>
> On Sat, 17 Jan 2004 16:07:39 -0500, Lee Ayrton <layrton@panix.com>
> wrote:
>
> >
> >Have you checked the voltage at the coil? If your `82 is the same as my
> >`79, the coil gets full battery voltage while cranking from a terminal on
> >the starter relay, then drops to a lower voltage (via a resistive link
> >spliced into the harness) while running. If there's a corroded splice or
> >terminal in the "run" circuit someplace, you'll get easy starts (full
> >voltage) but crappy running (low or intermittant voltage).
> >
> >Just a thought.
> >
> >
> >On Thu, 15 Jan 2004 pomerom@yahoo.com wrote:
> >
> >> Trying to set the timing.
> >>
> >> Can't do it.
> >>
> >> Engine starts easily and runs, but very ragged.
> >>
> >> Intermittent no spark to each plug. Will show a spark correctly for 1
> >> or 2 or 5 or whatever correct rotations; then go away for various
> >> periods from momentary to up to several seconds; then more of the
> >> same. Apparent at idle and at higher rpm's -- with the only
> >> difference in the rate of spark obviously correlated with engine
> >> speed.
> >>
> >> Can be observed by putting the inductive timing light sensor on #1; or
> >> any other cylinder wire; or on the coil-to-distributor wires.
> >>
> >> Got a second inductive timing light. Same exact symptoms. (Both
> >> timing lights work just fine on my 90 Cherokee).
> >>
> >> Battery is good and fully charged. Weather is warm (I live in
> >> Florida). Have replaced the coil, the distributor cap & rotor, the
> >> plugs, and the plug wires. Nothing made any difference.
> >>
> >> No evidence of any corrosion or other obvious mechanical issues inside
> >> the distributor or elsewhere.
> >>
> >> Have owned the vehicle since new so I know there have been no
> >> modifications to the electrical system.
> >>
> >> Help please -- what do I check now. What should I do??
> >>
> >> Thanks ......
> >>
> >> Mike
> >> Michael Pomeroy
> >>
>
> Michael Pomeroy

pomerom@yahoo.com

Mike

Checked the fuel filter. (It is only 6 months old, probably has 250
miles on the motor since then.)

It WAS upside down based upon your description below.

Fixed; right-side-up now.

But no difference in the problem noted.

Mike

On Fri, 16 Jan 2004 09:35:33 -0500, Mike Romain <romainm@sympatico.ca>
wrote:

>A bad ground comes to mind next, then a bad ignition module.
>
>I test the grounds with a booster cable. I run it from the battery
>negative to the engine block and see what happens, if the same I then
>tag the distributor itself with the booster cable. (I have seen a few
>distributors loose their ground due to surface rust)
>
>If still no joy I then tag the firewall with the booster cable and then
>the ignition module itself. The module needs a good ground or it will
>try and steal one through the distributor.
>
>How is the fuel filter? A plugged up one can starve the carb for fuel
>at idle and cause the inductive miss you see. When the pump comes up in
>speed, it can force gas through a partially plugged filter.
>
>So can a fuel filter that is in upside down. If upside down, it will
>pump too much gas back to the tank at idle and can starve the carb for
>fuel.
>
>Just a few more thoughts for you...
>
>Mike
>
>pomerom@yahoo.com wrote:
>>
>> Mike,
>>
>> Didn't say this in the initial posting because I didn't think it
>> relevant, but original carb is gone and there is a Weber on there now.
>>
>> And I don't know for sure, but looking back and thinking back I
>> believe I've had this problem for some time -- even when the original
>> carburator was still in place. (The Scrambler is driven on an
>> irregular basis.)
>>
>> Still no joy -- more suggestions please ......
>>
>> Mike
>>
>> On Thu, 15 Jan 2004 09:44:58 -0500, Mike Romain <romainm@sympatico.ca>
>> wrote:
>>
>> >I got suckered with those symptoms and an inductive timing light and
>> >went after parts.
>> >
>> >It was plugged idle tubes in the carb. The lack of or wrong amount of
>> >gas reaching the plugs affected the timing light implying a spark
>> >problem.
>> >
>> >I figured it out after there was nothing electrical left to change...
>> >
>> >Here is a link on the idle tubes and the fix for them. I can fix them
>> >from the top in about 15 minutes now that I know how to do it.
>> >
>> >http://www.off-road.com/jeep/tech/engine/carter.html
>> >
>> >Also a kit for that carb is only twenty bucks or so and should be done
>> >with every major tuneup or spark plug change.
>> >
>> >Mike
>> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> >88 Cherokee 235 BFG AT's
>> >
>> >pomerom@yahoo.com wrote:
>> >>
>> >> Trying to set the timing.
>> >>
>> >> Can't do it.
>> >>
>> >> Engine starts easily and runs, but very ragged.
>> >>
>> >> Intermittent no spark to each plug. Will show a spark correctly for 1
>> >> or 2 or 5 or whatever correct rotations; then go away for various
>> >> periods from momentary to up to several seconds; then more of the
>> >> same. Apparent at idle and at higher rpm's -- with the only
>> >> difference in the rate of spark obviously correlated with engine
>> >> speed.
>> >>
>> >> Can be observed by putting the inductive timing light sensor on #1; or
>> >> any other cylinder wire; or on the coil-to-distributor wires.
>> >>
>> >> Got a second inductive timing light. Same exact symptoms. (Both
>> >> timing lights work just fine on my 90 Cherokee).
>> >>
>> >> Battery is good and fully charged. Weather is warm (I live in
>> >> Florida). Have replaced the coil, the distributor cap & rotor, the
>> >> plugs, and the plug wires. Nothing made any difference.
>> >>
>> >> No evidence of any corrosion or other obvious mechanical issues inside
>> >> the distributor or elsewhere.
>> >>
>> >> Have owned the vehicle since new so I know there have been no
>> >> modifications to the electrical system.
>> >>
>> >> Help please -- what do I check now. What should I do??
>> >>
>> >> Thanks ......
>> >>
>> >> Mike
>> >> Michael Pomeroy
>>
>> Michael Pomeroy

Michael Pomeroy

pomerom@yahoo.com

Mike

Checked the fuel filter. (It is only 6 months old, probably has 250
miles on the motor since then.)

It WAS upside down based upon your description below.

Fixed; right-side-up now.

But no difference in the problem noted.

Mike

On Fri, 16 Jan 2004 09:35:33 -0500, Mike Romain <romainm@sympatico.ca>
wrote:

>A bad ground comes to mind next, then a bad ignition module.
>
>I test the grounds with a booster cable. I run it from the battery
>negative to the engine block and see what happens, if the same I then
>tag the distributor itself with the booster cable. (I have seen a few
>distributors loose their ground due to surface rust)
>
>If still no joy I then tag the firewall with the booster cable and then
>the ignition module itself. The module needs a good ground or it will
>try and steal one through the distributor.
>
>How is the fuel filter? A plugged up one can starve the carb for fuel
>at idle and cause the inductive miss you see. When the pump comes up in
>speed, it can force gas through a partially plugged filter.
>
>So can a fuel filter that is in upside down. If upside down, it will
>pump too much gas back to the tank at idle and can starve the carb for
>fuel.
>
>Just a few more thoughts for you...
>
>Mike
>
>pomerom@yahoo.com wrote:
>>
>> Mike,
>>
>> Didn't say this in the initial posting because I didn't think it
>> relevant, but original carb is gone and there is a Weber on there now.
>>
>> And I don't know for sure, but looking back and thinking back I
>> believe I've had this problem for some time -- even when the original
>> carburator was still in place. (The Scrambler is driven on an
>> irregular basis.)
>>
>> Still no joy -- more suggestions please ......
>>
>> Mike
>>
>> On Thu, 15 Jan 2004 09:44:58 -0500, Mike Romain <romainm@sympatico.ca>
>> wrote:
>>
>> >I got suckered with those symptoms and an inductive timing light and
>> >went after parts.
>> >
>> >It was plugged idle tubes in the carb. The lack of or wrong amount of
>> >gas reaching the plugs affected the timing light implying a spark
>> >problem.
>> >
>> >I figured it out after there was nothing electrical left to change...
>> >
>> >Here is a link on the idle tubes and the fix for them. I can fix them
>> >from the top in about 15 minutes now that I know how to do it.
>> >
>> >http://www.off-road.com/jeep/tech/engine/carter.html
>> >
>> >Also a kit for that carb is only twenty bucks or so and should be done
>> >with every major tuneup or spark plug change.
>> >
>> >Mike
>> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> >88 Cherokee 235 BFG AT's
>> >
>> >pomerom@yahoo.com wrote:
>> >>
>> >> Trying to set the timing.
>> >>
>> >> Can't do it.
>> >>
>> >> Engine starts easily and runs, but very ragged.
>> >>
>> >> Intermittent no spark to each plug. Will show a spark correctly for 1
>> >> or 2 or 5 or whatever correct rotations; then go away for various
>> >> periods from momentary to up to several seconds; then more of the
>> >> same. Apparent at idle and at higher rpm's -- with the only
>> >> difference in the rate of spark obviously correlated with engine
>> >> speed.
>> >>
>> >> Can be observed by putting the inductive timing light sensor on #1; or
>> >> any other cylinder wire; or on the coil-to-distributor wires.
>> >>
>> >> Got a second inductive timing light. Same exact symptoms. (Both
>> >> timing lights work just fine on my 90 Cherokee).
>> >>
>> >> Battery is good and fully charged. Weather is warm (I live in
>> >> Florida). Have replaced the coil, the distributor cap & rotor, the
>> >> plugs, and the plug wires. Nothing made any difference.
>> >>
>> >> No evidence of any corrosion or other obvious mechanical issues inside
>> >> the distributor or elsewhere.
>> >>
>> >> Have owned the vehicle since new so I know there have been no
>> >> modifications to the electrical system.
>> >>
>> >> Help please -- what do I check now. What should I do??
>> >>
>> >> Thanks ......
>> >>
>> >> Mike
>> >> Michael Pomeroy
>>
>> Michael Pomeroy

Michael Pomeroy

pomerom@yahoo.com

Mike

Checked the fuel filter. (It is only 6 months old, probably has 250
miles on the motor since then.)

It WAS upside down based upon your description below.

Fixed; right-side-up now.

But no difference in the problem noted.

Mike

On Fri, 16 Jan 2004 09:35:33 -0500, Mike Romain <romainm@sympatico.ca>
wrote:

>A bad ground comes to mind next, then a bad ignition module.
>
>I test the grounds with a booster cable. I run it from the battery
>negative to the engine block and see what happens, if the same I then
>tag the distributor itself with the booster cable. (I have seen a few
>distributors loose their ground due to surface rust)
>
>If still no joy I then tag the firewall with the booster cable and then
>the ignition module itself. The module needs a good ground or it will
>try and steal one through the distributor.
>
>How is the fuel filter? A plugged up one can starve the carb for fuel
>at idle and cause the inductive miss you see. When the pump comes up in
>speed, it can force gas through a partially plugged filter.
>
>So can a fuel filter that is in upside down. If upside down, it will
>pump too much gas back to the tank at idle and can starve the carb for
>fuel.
>
>Just a few more thoughts for you...
>
>Mike
>
>pomerom@yahoo.com wrote:
>>
>> Mike,
>>
>> Didn't say this in the initial posting because I didn't think it
>> relevant, but original carb is gone and there is a Weber on there now.
>>
>> And I don't know for sure, but looking back and thinking back I
>> believe I've had this problem for some time -- even when the original
>> carburator was still in place. (The Scrambler is driven on an
>> irregular basis.)
>>
>> Still no joy -- more suggestions please ......
>>
>> Mike
>>
>> On Thu, 15 Jan 2004 09:44:58 -0500, Mike Romain <romainm@sympatico.ca>
>> wrote:
>>
>> >I got suckered with those symptoms and an inductive timing light and
>> >went after parts.
>> >
>> >It was plugged idle tubes in the carb. The lack of or wrong amount of
>> >gas reaching the plugs affected the timing light implying a spark
>> >problem.
>> >
>> >I figured it out after there was nothing electrical left to change...
>> >
>> >Here is a link on the idle tubes and the fix for them. I can fix them
>> >from the top in about 15 minutes now that I know how to do it.
>> >
>> >http://www.off-road.com/jeep/tech/engine/carter.html
>> >
>> >Also a kit for that carb is only twenty bucks or so and should be done
>> >with every major tuneup or spark plug change.
>> >
>> >Mike
>> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> >88 Cherokee 235 BFG AT's
>> >
>> >pomerom@yahoo.com wrote:
>> >>
>> >> Trying to set the timing.
>> >>
>> >> Can't do it.
>> >>
>> >> Engine starts easily and runs, but very ragged.
>> >>
>> >> Intermittent no spark to each plug. Will show a spark correctly for 1
>> >> or 2 or 5 or whatever correct rotations; then go away for various
>> >> periods from momentary to up to several seconds; then more of the
>> >> same. Apparent at idle and at higher rpm's -- with the only
>> >> difference in the rate of spark obviously correlated with engine
>> >> speed.
>> >>
>> >> Can be observed by putting the inductive timing light sensor on #1; or
>> >> any other cylinder wire; or on the coil-to-distributor wires.
>> >>
>> >> Got a second inductive timing light. Same exact symptoms. (Both
>> >> timing lights work just fine on my 90 Cherokee).
>> >>
>> >> Battery is good and fully charged. Weather is warm (I live in
>> >> Florida). Have replaced the coil, the distributor cap & rotor, the
>> >> plugs, and the plug wires. Nothing made any difference.
>> >>
>> >> No evidence of any corrosion or other obvious mechanical issues inside
>> >> the distributor or elsewhere.
>> >>
>> >> Have owned the vehicle since new so I know there have been no
>> >> modifications to the electrical system.
>> >>
>> >> Help please -- what do I check now. What should I do??
>> >>
>> >> Thanks ......
>> >>
>> >> Mike
>> >> Michael Pomeroy
>>
>> Michael Pomeroy

Michael Pomeroy

Mike Romain

All speeds sure does change things.....

Do you have a computer in that 82? Or are you lucky and it was just
before them?

For the cost, changing the fuel filter can't hurt....

I would also try unplugging the plug at the side of the alternator as
well to see what happens. Your alternator sounds ok, but a short in
there can pull the coil signal down. The small brown wire to the
alternator excite tags the coil power. Just a thought.

I also would pull the dipstick and have a smell of the oil. If the fuel
pump is failing it will pump some gas into the oil and the smell will be
there.

Do you have a tachometer? If so, factory or aftermarket? I have seen
aftermarket tachs go bad and cause a spark miss.

Mike

pomerom@yahoo.com wrote:
>
> Mike
>
> Tried all the suggestions here except the fuel filter.
>
> Took the ignition module back off, scrapped some bare metal from the
> fender where it mounts and connects, and made sure it was tightened
> back down well. No help.
>
> Took some booster cables and tried all of the areas you suggested.
> Great suggestion I'd have never thought of, and to keep in the mind
> for the future.
>
> But no improvement noted at all.
>
> And this engine is missing bad, even when revved up. It is not
> driveable. But the problem is not just at idle -- it is at ALL engine
> speeds.. From a fast idle, which is what is required to keep it
> running, all the way through a fast RPM.
>
> And this may not be the only problem I have, but with either of the
> two timing lights I have you can see the erratic flashing at ALL
> engine RPMs. (It seems more erratic at slower RPM, but that may be my
> imagination or misinterpretation.
>
> (And, of course, I had to check out the timing lights again to make
> certain what I was seeing was real and not an artifact of the light
> itself. So I again put one of them on my 91 Cherokee and it worked
> just fine.)
>
> Mike
>
> On Fri, 16 Jan 2004 09:35:33 -0500, Mike Romain <romainm@sympatico.ca>
> wrote:
>
> >A bad ground comes to mind next, then a bad ignition module.
> >
> >I test the grounds with a booster cable. I run it from the battery
> >negative to the engine block and see what happens, if the same I then
> >tag the distributor itself with the booster cable. (I have seen a few
> >distributors loose their ground due to surface rust)
> >
> >If still no joy I then tag the firewall with the booster cable and then
> >the ignition module itself. The module needs a good ground or it will
> >try and steal one through the distributor.
> >
> >How is the fuel filter? A plugged up one can starve the carb for fuel
> >at idle and cause the inductive miss you see. When the pump comes up in
> >speed, it can force gas through a partially plugged filter.
> >
> >So can a fuel filter that is in upside down. If upside down, it will
> >pump too much gas back to the tank at idle and can starve the carb for
> >fuel.
> >
> >Just a few more thoughts for you...
> >
> >Mike
> >
> >pomerom@yahoo.com wrote:
> >>
> >> Mike,
> >>
> >> Didn't say this in the initial posting because I didn't think it
> >> relevant, but original carb is gone and there is a Weber on there now.
> >>
> >> And I don't know for sure, but looking back and thinking back I
> >> believe I've had this problem for some time -- even when the original
> >> carburator was still in place. (The Scrambler is driven on an
> >> irregular basis.)
> >>
> >> Still no joy -- more suggestions please ......
> >>
> >> Mike
> >>
> >> On Thu, 15 Jan 2004 09:44:58 -0500, Mike Romain <romainm@sympatico.ca>
> >> wrote:
> >>
> >> >I got suckered with those symptoms and an inductive timing light and
> >> >went after parts.
> >> >
> >> >It was plugged idle tubes in the carb. The lack of or wrong amount of
> >> >gas reaching the plugs affected the timing light implying a spark
> >> >problem.
> >> >
> >> >I figured it out after there was nothing electrical left to change...
> >> >
> >> >Here is a link on the idle tubes and the fix for them. I can fix them
> >> >from the top in about 15 minutes now that I know how to do it.
> >> >
> >> >http://www.off-road.com/jeep/tech/engine/carter.html
> >> >
> >> >Also a kit for that carb is only twenty bucks or so and should be done
> >> >with every major tuneup or spark plug change.
> >> >
> >> >Mike
> >> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >> >88 Cherokee 235 BFG AT's
> >> >
> >> >pomerom@yahoo.com wrote:
> >> >>
> >> >> Trying to set the timing.
> >> >>
> >> >> Can't do it.
> >> >>
> >> >> Engine starts easily and runs, but very ragged.
> >> >>
> >> >> Intermittent no spark to each plug. Will show a spark correctly for 1
> >> >> or 2 or 5 or whatever correct rotations; then go away for various
> >> >> periods from momentary to up to several seconds; then more of the
> >> >> same. Apparent at idle and at higher rpm's -- with the only
> >> >> difference in the rate of spark obviously correlated with engine
> >> >> speed.
> >> >>
> >> >> Can be observed by putting the inductive timing light sensor on #1; or
> >> >> any other cylinder wire; or on the coil-to-distributor wires.
> >> >>
> >> >> Got a second inductive timing light. Same exact symptoms. (Both
> >> >> timing lights work just fine on my 90 Cherokee).
> >> >>
> >> >> Battery is good and fully charged. Weather is warm (I live in
> >> >> Florida). Have replaced the coil, the distributor cap & rotor, the
> >> >> plugs, and the plug wires. Nothing made any difference.
> >> >>
> >> >> No evidence of any corrosion or other obvious mechanical issues inside
> >> >> the distributor or elsewhere.
> >> >>
> >> >> Have owned the vehicle since new so I know there have been no
> >> >> modifications to the electrical system.
> >> >>
> >> >> Help please -- what do I check now. What should I do??
> >> >>
> >> >> Thanks ......
> >> >>
> >> >> Mike
> >> >> Michael Pomeroy
> >>
> >> Michael Pomeroy
>
> Michael Pomeroy

Mike Romain

All speeds sure does change things.....

Do you have a computer in that 82? Or are you lucky and it was just
before them?

For the cost, changing the fuel filter can't hurt....

I would also try unplugging the plug at the side of the alternator as
well to see what happens. Your alternator sounds ok, but a short in
there can pull the coil signal down. The small brown wire to the
alternator excite tags the coil power. Just a thought.

I also would pull the dipstick and have a smell of the oil. If the fuel
pump is failing it will pump some gas into the oil and the smell will be
there.

Do you have a tachometer? If so, factory or aftermarket? I have seen
aftermarket tachs go bad and cause a spark miss.

Mike

pomerom@yahoo.com wrote:
>
> Mike
>
> Tried all the suggestions here except the fuel filter.
>
> Took the ignition module back off, scrapped some bare metal from the
> fender where it mounts and connects, and made sure it was tightened
> back down well. No help.
>
> Took some booster cables and tried all of the areas you suggested.
> Great suggestion I'd have never thought of, and to keep in the mind
> for the future.
>
> But no improvement noted at all.
>
> And this engine is missing bad, even when revved up. It is not
> driveable. But the problem is not just at idle -- it is at ALL engine
> speeds.. From a fast idle, which is what is required to keep it
> running, all the way through a fast RPM.
>
> And this may not be the only problem I have, but with either of the
> two timing lights I have you can see the erratic flashing at ALL
> engine RPMs. (It seems more erratic at slower RPM, but that may be my
> imagination or misinterpretation.
>
> (And, of course, I had to check out the timing lights again to make
> certain what I was seeing was real and not an artifact of the light
> itself. So I again put one of them on my 91 Cherokee and it worked
> just fine.)
>
> Mike
>
> On Fri, 16 Jan 2004 09:35:33 -0500, Mike Romain <romainm@sympatico.ca>
> wrote:
>
> >A bad ground comes to mind next, then a bad ignition module.
> >
> >I test the grounds with a booster cable. I run it from the battery
> >negative to the engine block and see what happens, if the same I then
> >tag the distributor itself with the booster cable. (I have seen a few
> >distributors loose their ground due to surface rust)
> >
> >If still no joy I then tag the firewall with the booster cable and then
> >the ignition module itself. The module needs a good ground or it will
> >try and steal one through the distributor.
> >
> >How is the fuel filter? A plugged up one can starve the carb for fuel
> >at idle and cause the inductive miss you see. When the pump comes up in
> >speed, it can force gas through a partially plugged filter.
> >
> >So can a fuel filter that is in upside down. If upside down, it will
> >pump too much gas back to the tank at idle and can starve the carb for
> >fuel.
> >
> >Just a few more thoughts for you...
> >
> >Mike
> >
> >pomerom@yahoo.com wrote:
> >>
> >> Mike,
> >>
> >> Didn't say this in the initial posting because I didn't think it
> >> relevant, but original carb is gone and there is a Weber on there now.
> >>
> >> And I don't know for sure, but looking back and thinking back I
> >> believe I've had this problem for some time -- even when the original
> >> carburator was still in place. (The Scrambler is driven on an
> >> irregular basis.)
> >>
> >> Still no joy -- more suggestions please ......
> >>
> >> Mike
> >>
> >> On Thu, 15 Jan 2004 09:44:58 -0500, Mike Romain <romainm@sympatico.ca>
> >> wrote:
> >>
> >> >I got suckered with those symptoms and an inductive timing light and
> >> >went after parts.
> >> >
> >> >It was plugged idle tubes in the carb. The lack of or wrong amount of
> >> >gas reaching the plugs affected the timing light implying a spark
> >> >problem.
> >> >
> >> >I figured it out after there was nothing electrical left to change...
> >> >
> >> >Here is a link on the idle tubes and the fix for them. I can fix them
> >> >from the top in about 15 minutes now that I know how to do it.
> >> >
> >> >http://www.off-road.com/jeep/tech/engine/carter.html
> >> >
> >> >Also a kit for that carb is only twenty bucks or so and should be done
> >> >with every major tuneup or spark plug change.
> >> >
> >> >Mike
> >> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >> >88 Cherokee 235 BFG AT's
> >> >
> >> >pomerom@yahoo.com wrote:
> >> >>
> >> >> Trying to set the timing.
> >> >>
> >> >> Can't do it.
> >> >>
> >> >> Engine starts easily and runs, but very ragged.
> >> >>
> >> >> Intermittent no spark to each plug. Will show a spark correctly for 1
> >> >> or 2 or 5 or whatever correct rotations; then go away for various
> >> >> periods from momentary to up to several seconds; then more of the
> >> >> same. Apparent at idle and at higher rpm's -- with the only
> >> >> difference in the rate of spark obviously correlated with engine
> >> >> speed.
> >> >>
> >> >> Can be observed by putting the inductive timing light sensor on #1; or
> >> >> any other cylinder wire; or on the coil-to-distributor wires.
> >> >>
> >> >> Got a second inductive timing light. Same exact symptoms. (Both
> >> >> timing lights work just fine on my 90 Cherokee).
> >> >>
> >> >> Battery is good and fully charged. Weather is warm (I live in
> >> >> Florida). Have replaced the coil, the distributor cap & rotor, the
> >> >> plugs, and the plug wires. Nothing made any difference.
> >> >>
> >> >> No evidence of any corrosion or other obvious mechanical issues inside
> >> >> the distributor or elsewhere.
> >> >>
> >> >> Have owned the vehicle since new so I know there have been no
> >> >> modifications to the electrical system.
> >> >>
> >> >> Help please -- what do I check now. What should I do??
> >> >>
> >> >> Thanks ......
> >> >>
> >> >> Mike
> >> >> Michael Pomeroy
> >>
> >> Michael Pomeroy
>
> Michael Pomeroy

Mike Romain

All speeds sure does change things.....

Do you have a computer in that 82? Or are you lucky and it was just
before them?

For the cost, changing the fuel filter can't hurt....

I would also try unplugging the plug at the side of the alternator as
well to see what happens. Your alternator sounds ok, but a short in
there can pull the coil signal down. The small brown wire to the
alternator excite tags the coil power. Just a thought.

I also would pull the dipstick and have a smell of the oil. If the fuel
pump is failing it will pump some gas into the oil and the smell will be
there.

Do you have a tachometer? If so, factory or aftermarket? I have seen
aftermarket tachs go bad and cause a spark miss.

Mike

pomerom@yahoo.com wrote:
>
> Mike
>
> Tried all the suggestions here except the fuel filter.
>
> Took the ignition module back off, scrapped some bare metal from the
> fender where it mounts and connects, and made sure it was tightened
> back down well. No help.
>
> Took some booster cables and tried all of the areas you suggested.
> Great suggestion I'd have never thought of, and to keep in the mind
> for the future.
>
> But no improvement noted at all.
>
> And this engine is missing bad, even when revved up. It is not
> driveable. But the problem is not just at idle -- it is at ALL engine
> speeds.. From a fast idle, which is what is required to keep it
> running, all the way through a fast RPM.
>
> And this may not be the only problem I have, but with either of the
> two timing lights I have you can see the erratic flashing at ALL
> engine RPMs. (It seems more erratic at slower RPM, but that may be my
> imagination or misinterpretation.
>
> (And, of course, I had to check out the timing lights again to make
> certain what I was seeing was real and not an artifact of the light
> itself. So I again put one of them on my 91 Cherokee and it worked
> just fine.)
>
> Mike
>
> On Fri, 16 Jan 2004 09:35:33 -0500, Mike Romain <romainm@sympatico.ca>
> wrote:
>
> >A bad ground comes to mind next, then a bad ignition module.
> >
> >I test the grounds with a booster cable. I run it from the battery
> >negative to the engine block and see what happens, if the same I then
> >tag the distributor itself with the booster cable. (I have seen a few
> >distributors loose their ground due to surface rust)
> >
> >If still no joy I then tag the firewall with the booster cable and then
> >the ignition module itself. The module needs a good ground or it will
> >try and steal one through the distributor.
> >
> >How is the fuel filter? A plugged up one can starve the carb for fuel
> >at idle and cause the inductive miss you see. When the pump comes up in
> >speed, it can force gas through a partially plugged filter.
> >
> >So can a fuel filter that is in upside down. If upside down, it will
> >pump too much gas back to the tank at idle and can starve the carb for
> >fuel.
> >
> >Just a few more thoughts for you...
> >
> >Mike
> >
> >pomerom@yahoo.com wrote:
> >>
> >> Mike,
> >>
> >> Didn't say this in the initial posting because I didn't think it
> >> relevant, but original carb is gone and there is a Weber on there now.
> >>
> >> And I don't know for sure, but looking back and thinking back I
> >> believe I've had this problem for some time -- even when the original
> >> carburator was still in place. (The Scrambler is driven on an
> >> irregular basis.)
> >>
> >> Still no joy -- more suggestions please ......
> >>
> >> Mike
> >>
> >> On Thu, 15 Jan 2004 09:44:58 -0500, Mike Romain <romainm@sympatico.ca>
> >> wrote:
> >>
> >> >I got suckered with those symptoms and an inductive timing light and
> >> >went after parts.
> >> >
> >> >It was plugged idle tubes in the carb. The lack of or wrong amount of
> >> >gas reaching the plugs affected the timing light implying a spark
> >> >problem.
> >> >
> >> >I figured it out after there was nothing electrical left to change...
> >> >
> >> >Here is a link on the idle tubes and the fix for them. I can fix them
> >> >from the top in about 15 minutes now that I know how to do it.
> >> >
> >> >http://www.off-road.com/jeep/tech/engine/carter.html
> >> >
> >> >Also a kit for that carb is only twenty bucks or so and should be done
> >> >with every major tuneup or spark plug change.
> >> >
> >> >Mike
> >> >86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >> >88 Cherokee 235 BFG AT's
> >> >
> >> >pomerom@yahoo.com wrote:
> >> >>
> >> >> Trying to set the timing.
> >> >>
> >> >> Can't do it.
> >> >>
> >> >> Engine starts easily and runs, but very ragged.
> >> >>
> >> >> Intermittent no spark to each plug. Will show a spark correctly for 1
> >> >> or 2 or 5 or whatever correct rotations; then go away for various
> >> >> periods from momentary to up to several seconds; then more of the
> >> >> same. Apparent at idle and at higher rpm's -- with the only
> >> >> difference in the rate of spark obviously correlated with engine
> >> >> speed.
> >> >>
> >> >> Can be observed by putting the inductive timing light sensor on #1; or
> >> >> any other cylinder wire; or on the coil-to-distributor wires.
> >> >>
> >> >> Got a second inductive timing light. Same exact symptoms. (Both
> >> >> timing lights work just fine on my 90 Cherokee).
> >> >>
> >> >> Battery is good and fully charged. Weather is warm (I live in
> >> >> Florida). Have replaced the coil, the distributor cap & rotor, the
> >> >> plugs, and the plug wires. Nothing made any difference.
> >> >>
> >> >> No evidence of any corrosion or other obvious mechanical issues inside
> >> >> the distributor or elsewhere.
> >> >>
> >> >> Have owned the vehicle since new so I know there have been no
> >> >> modifications to the electrical system.
> >> >>
> >> >> Help please -- what do I check now. What should I do??
> >> >>
> >> >> Thanks ......
> >> >>
> >> >> Mike
> >> >> Michael Pomeroy
> >>
> >> Michael Pomeroy
>
> Michael Pomeroy

Lee Ayrton

[Bottom-posted this time for clarity]

On Mon, 19 Jan 2004 pomerom@yahoo.com wrote:

> terminal to the red wire on top of the coil itself):
> 1: With engine off but key on = 7.6
> 2: With engine running at a fast (though ragged missing) idle = 10.9-
> 11.2
>
> And, note, this 10.9-11.2 was bouncing around constantly, not staying
> steady at all.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I wonder, the load of the coil shouldn't pull the voltage down enough to
make the meter bounce badly, and just because a meter sees voltage it
doesn't mean that there's enough current there to be useful.

Try this: Pull the connector off the coil (carefully, because the clips
are easy to break when they get old), it is a half-moon shaped affair that
mates with two posts on the coil. The (+) wire is fed constant
7-something volt power from the ignition switch by way of a resistive link
spliced into the harness (someplace along the firewall) when the switch in
is the "run" position. It is also fed full battery voltage by way of the
"I" terminal (the one closest to the battery cable in the Ford systems) on
the starter relay, but only while starting. The (-) wire goes back to
your ignition module on the left fender and only carries current when the
ignition module is telling the coil to fire. Make sure that they are
really making good clean contact with the posts. Put it back together.

Then: Rig a jumper to the red (coil +) connector at the coil, protect the
free end somehow so it doesn't make contact with anything and smoke your
wiring harness. Start the engine and touch your jumper to the + battery
terminal -- what you're doing here is bypassing all the harness wiring
between the battery and the coil. Don't leave it on too long because
you're over-volting the coil. If the engine straightens up and runs
smooth, you've demonstrated that there's a problem in the system that
feeds the coil. That narrows it down to:

- The connection at the coil.
- The splice where the wire for the "I" terminal comes in.
- The splice where the resistive link (a stiff wire a couple of feet
long with a loose, rubbery insulator, probably a different color red
from everything else) comes in. Probably at the "I" terminal.
- The splice where the resistive link goes back into the harness.
- The bulkhead feed-through at the fire wall.
- The connector at the bottom of the steering column.
- The ignition switch.
- Any non-factory splices POs made in that line under the hood looking for
B+ sources.


Disclaimer: I'm not a mechanic. I'm only telling you what I would try.
Doing any of this is completely at your own risk.

Lee Ayrton

[Bottom-posted this time for clarity]

On Mon, 19 Jan 2004 pomerom@yahoo.com wrote:

> terminal to the red wire on top of the coil itself):
> 1: With engine off but key on = 7.6
> 2: With engine running at a fast (though ragged missing) idle = 10.9-
> 11.2
>
> And, note, this 10.9-11.2 was bouncing around constantly, not staying
> steady at all.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I wonder, the load of the coil shouldn't pull the voltage down enough to
make the meter bounce badly, and just because a meter sees voltage it
doesn't mean that there's enough current there to be useful.

Try this: Pull the connector off the coil (carefully, because the clips
are easy to break when they get old), it is a half-moon shaped affair that
mates with two posts on the coil. The (+) wire is fed constant
7-something volt power from the ignition switch by way of a resistive link
spliced into the harness (someplace along the firewall) when the switch in
is the "run" position. It is also fed full battery voltage by way of the
"I" terminal (the one closest to the battery cable in the Ford systems) on
the starter relay, but only while starting. The (-) wire goes back to
your ignition module on the left fender and only carries current when the
ignition module is telling the coil to fire. Make sure that they are
really making good clean contact with the posts. Put it back together.

Then: Rig a jumper to the red (coil +) connector at the coil, protect the
free end somehow so it doesn't make contact with anything and smoke your
wiring harness. Start the engine and touch your jumper to the + battery
terminal -- what you're doing here is bypassing all the harness wiring
between the battery and the coil. Don't leave it on too long because
you're over-volting the coil. If the engine straightens up and runs
smooth, you've demonstrated that there's a problem in the system that
feeds the coil. That narrows it down to:

- The connection at the coil.
- The splice where the wire for the "I" terminal comes in.
- The splice where the resistive link (a stiff wire a couple of feet
long with a loose, rubbery insulator, probably a different color red
from everything else) comes in. Probably at the "I" terminal.
- The splice where the resistive link goes back into the harness.
- The bulkhead feed-through at the fire wall.
- The connector at the bottom of the steering column.
- The ignition switch.
- Any non-factory splices POs made in that line under the hood looking for
B+ sources.


Disclaimer: I'm not a mechanic. I'm only telling you what I would try.
Doing any of this is completely at your own risk.

Lee Ayrton

[Bottom-posted this time for clarity]

On Mon, 19 Jan 2004 pomerom@yahoo.com wrote:

> terminal to the red wire on top of the coil itself):
> 1: With engine off but key on = 7.6
> 2: With engine running at a fast (though ragged missing) idle = 10.9-
> 11.2
>
> And, note, this 10.9-11.2 was bouncing around constantly, not staying
> steady at all.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I wonder, the load of the coil shouldn't pull the voltage down enough to
make the meter bounce badly, and just because a meter sees voltage it
doesn't mean that there's enough current there to be useful.

Try this: Pull the connector off the coil (carefully, because the clips
are easy to break when they get old), it is a half-moon shaped affair that
mates with two posts on the coil. The (+) wire is fed constant
7-something volt power from the ignition switch by way of a resistive link
spliced into the harness (someplace along the firewall) when the switch in
is the "run" position. It is also fed full battery voltage by way of the
"I" terminal (the one closest to the battery cable in the Ford systems) on
the starter relay, but only while starting. The (-) wire goes back to
your ignition module on the left fender and only carries current when the
ignition module is telling the coil to fire. Make sure that they are
really making good clean contact with the posts. Put it back together.

Then: Rig a jumper to the red (coil +) connector at the coil, protect the
free end somehow so it doesn't make contact with anything and smoke your
wiring harness. Start the engine and touch your jumper to the + battery
terminal -- what you're doing here is bypassing all the harness wiring
between the battery and the coil. Don't leave it on too long because
you're over-volting the coil. If the engine straightens up and runs
smooth, you've demonstrated that there's a problem in the system that
feeds the coil. That narrows it down to:

- The connection at the coil.
- The splice where the wire for the "I" terminal comes in.
- The splice where the resistive link (a stiff wire a couple of feet
long with a loose, rubbery insulator, probably a different color red
from everything else) comes in. Probably at the "I" terminal.
- The splice where the resistive link goes back into the harness.
- The bulkhead feed-through at the fire wall.
- The connector at the bottom of the steering column.
- The ignition switch.
- Any non-factory splices POs made in that line under the hood looking for
B+ sources.


Disclaimer: I'm not a mechanic. I'm only telling you what I would try.
Doing any of this is completely at your own risk.