YJ error code - rough start
#1
Guest
Posts: n/a
YJ error code - rough start
93 YJ, automatic, I6, no A/C
rough starts (lots of cranking before turning over), low RPM's at idle
(500 - 600)
Runs well, sometimes at stops it will 'lug' a bit, I attribute this to the
low RPM's.
Error codes shown:
12 - Direct battery input to PCM was disconnected within the last 50 Key-on
cycles.
33 - An open or shorted condition detected in the A/C clutch relay circuit.
55 - end of diagnostic test
Battery is good.
I checked all connections for tightness and did a visual for any damaged
wires.
Cleaned terminals in the Power Distribution Center and added die-electric
grease to relay connections.
Verified that all fuses were good in PDC and internal fuse block.
No A/C so 33 should be a mute point.
So error code 12 has me stumped, more so given the fact that electricity is
magic to me (once the magic smoke comes out of the component it doesn't work
anymore) - any DETAILED tips for troubleshooting this further?
What is typical idle RPM?
TIA
paul
rough starts (lots of cranking before turning over), low RPM's at idle
(500 - 600)
Runs well, sometimes at stops it will 'lug' a bit, I attribute this to the
low RPM's.
Error codes shown:
12 - Direct battery input to PCM was disconnected within the last 50 Key-on
cycles.
33 - An open or shorted condition detected in the A/C clutch relay circuit.
55 - end of diagnostic test
Battery is good.
I checked all connections for tightness and did a visual for any damaged
wires.
Cleaned terminals in the Power Distribution Center and added die-electric
grease to relay connections.
Verified that all fuses were good in PDC and internal fuse block.
No A/C so 33 should be a mute point.
So error code 12 has me stumped, more so given the fact that electricity is
magic to me (once the magic smoke comes out of the component it doesn't work
anymore) - any DETAILED tips for troubleshooting this further?
What is typical idle RPM?
TIA
paul
#2
Guest
Posts: n/a
Re: YJ error code - rough start
paul wrote:
> 93 YJ, automatic, I6, no A/C
> rough starts (lots of cranking before turning over), low RPM's at idle
> (500 - 600)
> Runs well, sometimes at stops it will 'lug' a bit, I attribute this
> to the low RPM's.
> So error code 12 has me stumped
12 only indicates the battery was disconnected at one time. When you see
that along with lots of other codes then it can indicate a loose or corroded
battery terminal. I've yet to see a jeep that didn't throw code 12.
Try this.
Turn the key to on, wait for the fuel pump to stop.
Turn the key off, then back on, wait for the fuel pump to stop.
Now turn the key off, then start the engine.
If the engine starts right up then you have a leakdown problem
in the fuel line. It's either the pressure regulator in the
rail or the backflow valve in the pump.
Also, how long has it been since you replace the fuel filter?
Engine RPM of 500-600 is normal. Have you cleaned out the throttle
body and idle air passage? http://revbeergoggles.com/tb/tb.html
--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
> 93 YJ, automatic, I6, no A/C
> rough starts (lots of cranking before turning over), low RPM's at idle
> (500 - 600)
> Runs well, sometimes at stops it will 'lug' a bit, I attribute this
> to the low RPM's.
> So error code 12 has me stumped
12 only indicates the battery was disconnected at one time. When you see
that along with lots of other codes then it can indicate a loose or corroded
battery terminal. I've yet to see a jeep that didn't throw code 12.
Try this.
Turn the key to on, wait for the fuel pump to stop.
Turn the key off, then back on, wait for the fuel pump to stop.
Now turn the key off, then start the engine.
If the engine starts right up then you have a leakdown problem
in the fuel line. It's either the pressure regulator in the
rail or the backflow valve in the pump.
Also, how long has it been since you replace the fuel filter?
Engine RPM of 500-600 is normal. Have you cleaned out the throttle
body and idle air passage? http://revbeergoggles.com/tb/tb.html
--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
#3
Guest
Posts: n/a
Re: YJ error code - rough start
paul wrote:
> 93 YJ, automatic, I6, no A/C
> rough starts (lots of cranking before turning over), low RPM's at idle
> (500 - 600)
> Runs well, sometimes at stops it will 'lug' a bit, I attribute this
> to the low RPM's.
> So error code 12 has me stumped
12 only indicates the battery was disconnected at one time. When you see
that along with lots of other codes then it can indicate a loose or corroded
battery terminal. I've yet to see a jeep that didn't throw code 12.
Try this.
Turn the key to on, wait for the fuel pump to stop.
Turn the key off, then back on, wait for the fuel pump to stop.
Now turn the key off, then start the engine.
If the engine starts right up then you have a leakdown problem
in the fuel line. It's either the pressure regulator in the
rail or the backflow valve in the pump.
Also, how long has it been since you replace the fuel filter?
Engine RPM of 500-600 is normal. Have you cleaned out the throttle
body and idle air passage? http://revbeergoggles.com/tb/tb.html
--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
> 93 YJ, automatic, I6, no A/C
> rough starts (lots of cranking before turning over), low RPM's at idle
> (500 - 600)
> Runs well, sometimes at stops it will 'lug' a bit, I attribute this
> to the low RPM's.
> So error code 12 has me stumped
12 only indicates the battery was disconnected at one time. When you see
that along with lots of other codes then it can indicate a loose or corroded
battery terminal. I've yet to see a jeep that didn't throw code 12.
Try this.
Turn the key to on, wait for the fuel pump to stop.
Turn the key off, then back on, wait for the fuel pump to stop.
Now turn the key off, then start the engine.
If the engine starts right up then you have a leakdown problem
in the fuel line. It's either the pressure regulator in the
rail or the backflow valve in the pump.
Also, how long has it been since you replace the fuel filter?
Engine RPM of 500-600 is normal. Have you cleaned out the throttle
body and idle air passage? http://revbeergoggles.com/tb/tb.html
--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
#4
Guest
Posts: n/a
Re: YJ error code - rough start
paul wrote:
> 93 YJ, automatic, I6, no A/C
> rough starts (lots of cranking before turning over), low RPM's at idle
> (500 - 600)
> Runs well, sometimes at stops it will 'lug' a bit, I attribute this
> to the low RPM's.
> So error code 12 has me stumped
12 only indicates the battery was disconnected at one time. When you see
that along with lots of other codes then it can indicate a loose or corroded
battery terminal. I've yet to see a jeep that didn't throw code 12.
Try this.
Turn the key to on, wait for the fuel pump to stop.
Turn the key off, then back on, wait for the fuel pump to stop.
Now turn the key off, then start the engine.
If the engine starts right up then you have a leakdown problem
in the fuel line. It's either the pressure regulator in the
rail or the backflow valve in the pump.
Also, how long has it been since you replace the fuel filter?
Engine RPM of 500-600 is normal. Have you cleaned out the throttle
body and idle air passage? http://revbeergoggles.com/tb/tb.html
--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
> 93 YJ, automatic, I6, no A/C
> rough starts (lots of cranking before turning over), low RPM's at idle
> (500 - 600)
> Runs well, sometimes at stops it will 'lug' a bit, I attribute this
> to the low RPM's.
> So error code 12 has me stumped
12 only indicates the battery was disconnected at one time. When you see
that along with lots of other codes then it can indicate a loose or corroded
battery terminal. I've yet to see a jeep that didn't throw code 12.
Try this.
Turn the key to on, wait for the fuel pump to stop.
Turn the key off, then back on, wait for the fuel pump to stop.
Now turn the key off, then start the engine.
If the engine starts right up then you have a leakdown problem
in the fuel line. It's either the pressure regulator in the
rail or the backflow valve in the pump.
Also, how long has it been since you replace the fuel filter?
Engine RPM of 500-600 is normal. Have you cleaned out the throttle
body and idle air passage? http://revbeergoggles.com/tb/tb.html
--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
#5
Guest
Posts: n/a
Re: YJ error code - rough start
"DougW" <post.replies@invalid.address> wrote in message
news:pHXKg.9581$JR5.4280@dukeread11...
> Try this.
>
> Turn the key to on, wait for the fuel pump to stop.
> Turn the key off, then back on, wait for the fuel pump to stop.
> Now turn the key off, then start the engine.
Tried that, I can hear the fuel pump kicking in - still no success
>
> If the engine starts right up then you have a leakdown problem
> in the fuel line. It's either the pressure regulator in the
> rail or the backflow valve in the pump.
>
> Also, how long has it been since you replace the fuel filter?
About 2 years ago for the fuel filter.
Did notice a crack in the boot coming off the pressure regulator to the
manifold - did a temporary fix with electrical tape.
When the engine does start there is a noticable gas smell - would a bad
regulator show these symptoms?
>
> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
> body and idle air passage? http://revbeergoggles.com/tb/tb.html
Sprayed cleaner in it - would a dissassemble and thorough clean be more
appropriate?
THANKS!
paul
>
> --
> -- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
> HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
> Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
> Banks Header - and BEER, in the fridge!
>
>
#6
Guest
Posts: n/a
Re: YJ error code - rough start
"DougW" <post.replies@invalid.address> wrote in message
news:pHXKg.9581$JR5.4280@dukeread11...
> Try this.
>
> Turn the key to on, wait for the fuel pump to stop.
> Turn the key off, then back on, wait for the fuel pump to stop.
> Now turn the key off, then start the engine.
Tried that, I can hear the fuel pump kicking in - still no success
>
> If the engine starts right up then you have a leakdown problem
> in the fuel line. It's either the pressure regulator in the
> rail or the backflow valve in the pump.
>
> Also, how long has it been since you replace the fuel filter?
About 2 years ago for the fuel filter.
Did notice a crack in the boot coming off the pressure regulator to the
manifold - did a temporary fix with electrical tape.
When the engine does start there is a noticable gas smell - would a bad
regulator show these symptoms?
>
> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
> body and idle air passage? http://revbeergoggles.com/tb/tb.html
Sprayed cleaner in it - would a dissassemble and thorough clean be more
appropriate?
THANKS!
paul
>
> --
> -- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
> HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
> Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
> Banks Header - and BEER, in the fridge!
>
>
#7
Guest
Posts: n/a
Re: YJ error code - rough start
"DougW" <post.replies@invalid.address> wrote in message
news:pHXKg.9581$JR5.4280@dukeread11...
> Try this.
>
> Turn the key to on, wait for the fuel pump to stop.
> Turn the key off, then back on, wait for the fuel pump to stop.
> Now turn the key off, then start the engine.
Tried that, I can hear the fuel pump kicking in - still no success
>
> If the engine starts right up then you have a leakdown problem
> in the fuel line. It's either the pressure regulator in the
> rail or the backflow valve in the pump.
>
> Also, how long has it been since you replace the fuel filter?
About 2 years ago for the fuel filter.
Did notice a crack in the boot coming off the pressure regulator to the
manifold - did a temporary fix with electrical tape.
When the engine does start there is a noticable gas smell - would a bad
regulator show these symptoms?
>
> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
> body and idle air passage? http://revbeergoggles.com/tb/tb.html
Sprayed cleaner in it - would a dissassemble and thorough clean be more
appropriate?
THANKS!
paul
>
> --
> -- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
> HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
> Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
> Banks Header - and BEER, in the fridge!
>
>
#8
Guest
Posts: n/a
Re: YJ error code - rough start
paul wrote:
> "DougW" wrote
> About 2 years ago for the fuel filter.
> Did notice a crack in the boot coming off the pressure regulator to
> the manifold - did a temporary fix with electrical tape.
> When the engine does start there is a noticable gas smell - would a
> bad regulator show these symptoms?
Yes, if the internal diaphragm has broken it could be leaking and that
leak will run back into the intake. Easy enough to tell by simply
removing the vac line while the engine is running, and checking for gas.
So can leaky O-rings in the fuel rail quick connectors or leaking
injectors and their pressure side O-rings. Easiest way to check is to
wipe the rail and injectors down, run the engine, then go back with some
kleenex and see if you can pick up any fuel. Injectors can leak around
the electrical connection. If they are then they have to be replaced.
It is not necissary to replace them as a set, you can replace just one.
>> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
>> body and idle air passage? http://revbeergoggles.com/tb/tb.html
>
> Sprayed cleaner in it - would a dissassemble and thorough clean be
> more appropriate?
You wind up with a better job but it's not necessary. Sometimes I
take the idle air assembly off and dunk it in a glass of cleaner.
Just don't run the motor with the IAC out of its assembly. The
little pin will go shooting out and that's it for the stepper motor.
Should pick up a new gasket for the throttle body, since the old one
hardly ever seals back properly. That and it's cheap insurance in
case you rip the old one taking it out. And don't use a wrench on
the bolts, they only go in to 9 ft.lbs. That's easy to overdo with
just a screwdriver.
--
DougW
> "DougW" wrote
> About 2 years ago for the fuel filter.
> Did notice a crack in the boot coming off the pressure regulator to
> the manifold - did a temporary fix with electrical tape.
> When the engine does start there is a noticable gas smell - would a
> bad regulator show these symptoms?
Yes, if the internal diaphragm has broken it could be leaking and that
leak will run back into the intake. Easy enough to tell by simply
removing the vac line while the engine is running, and checking for gas.
So can leaky O-rings in the fuel rail quick connectors or leaking
injectors and their pressure side O-rings. Easiest way to check is to
wipe the rail and injectors down, run the engine, then go back with some
kleenex and see if you can pick up any fuel. Injectors can leak around
the electrical connection. If they are then they have to be replaced.
It is not necissary to replace them as a set, you can replace just one.
>> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
>> body and idle air passage? http://revbeergoggles.com/tb/tb.html
>
> Sprayed cleaner in it - would a dissassemble and thorough clean be
> more appropriate?
You wind up with a better job but it's not necessary. Sometimes I
take the idle air assembly off and dunk it in a glass of cleaner.
Just don't run the motor with the IAC out of its assembly. The
little pin will go shooting out and that's it for the stepper motor.
Should pick up a new gasket for the throttle body, since the old one
hardly ever seals back properly. That and it's cheap insurance in
case you rip the old one taking it out. And don't use a wrench on
the bolts, they only go in to 9 ft.lbs. That's easy to overdo with
just a screwdriver.
--
DougW
#9
Guest
Posts: n/a
Re: YJ error code - rough start
paul wrote:
> "DougW" wrote
> About 2 years ago for the fuel filter.
> Did notice a crack in the boot coming off the pressure regulator to
> the manifold - did a temporary fix with electrical tape.
> When the engine does start there is a noticable gas smell - would a
> bad regulator show these symptoms?
Yes, if the internal diaphragm has broken it could be leaking and that
leak will run back into the intake. Easy enough to tell by simply
removing the vac line while the engine is running, and checking for gas.
So can leaky O-rings in the fuel rail quick connectors or leaking
injectors and their pressure side O-rings. Easiest way to check is to
wipe the rail and injectors down, run the engine, then go back with some
kleenex and see if you can pick up any fuel. Injectors can leak around
the electrical connection. If they are then they have to be replaced.
It is not necissary to replace them as a set, you can replace just one.
>> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
>> body and idle air passage? http://revbeergoggles.com/tb/tb.html
>
> Sprayed cleaner in it - would a dissassemble and thorough clean be
> more appropriate?
You wind up with a better job but it's not necessary. Sometimes I
take the idle air assembly off and dunk it in a glass of cleaner.
Just don't run the motor with the IAC out of its assembly. The
little pin will go shooting out and that's it for the stepper motor.
Should pick up a new gasket for the throttle body, since the old one
hardly ever seals back properly. That and it's cheap insurance in
case you rip the old one taking it out. And don't use a wrench on
the bolts, they only go in to 9 ft.lbs. That's easy to overdo with
just a screwdriver.
--
DougW
> "DougW" wrote
> About 2 years ago for the fuel filter.
> Did notice a crack in the boot coming off the pressure regulator to
> the manifold - did a temporary fix with electrical tape.
> When the engine does start there is a noticable gas smell - would a
> bad regulator show these symptoms?
Yes, if the internal diaphragm has broken it could be leaking and that
leak will run back into the intake. Easy enough to tell by simply
removing the vac line while the engine is running, and checking for gas.
So can leaky O-rings in the fuel rail quick connectors or leaking
injectors and their pressure side O-rings. Easiest way to check is to
wipe the rail and injectors down, run the engine, then go back with some
kleenex and see if you can pick up any fuel. Injectors can leak around
the electrical connection. If they are then they have to be replaced.
It is not necissary to replace them as a set, you can replace just one.
>> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
>> body and idle air passage? http://revbeergoggles.com/tb/tb.html
>
> Sprayed cleaner in it - would a dissassemble and thorough clean be
> more appropriate?
You wind up with a better job but it's not necessary. Sometimes I
take the idle air assembly off and dunk it in a glass of cleaner.
Just don't run the motor with the IAC out of its assembly. The
little pin will go shooting out and that's it for the stepper motor.
Should pick up a new gasket for the throttle body, since the old one
hardly ever seals back properly. That and it's cheap insurance in
case you rip the old one taking it out. And don't use a wrench on
the bolts, they only go in to 9 ft.lbs. That's easy to overdo with
just a screwdriver.
--
DougW
#10
Guest
Posts: n/a
Re: YJ error code - rough start
paul wrote:
> "DougW" wrote
> About 2 years ago for the fuel filter.
> Did notice a crack in the boot coming off the pressure regulator to
> the manifold - did a temporary fix with electrical tape.
> When the engine does start there is a noticable gas smell - would a
> bad regulator show these symptoms?
Yes, if the internal diaphragm has broken it could be leaking and that
leak will run back into the intake. Easy enough to tell by simply
removing the vac line while the engine is running, and checking for gas.
So can leaky O-rings in the fuel rail quick connectors or leaking
injectors and their pressure side O-rings. Easiest way to check is to
wipe the rail and injectors down, run the engine, then go back with some
kleenex and see if you can pick up any fuel. Injectors can leak around
the electrical connection. If they are then they have to be replaced.
It is not necissary to replace them as a set, you can replace just one.
>> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
>> body and idle air passage? http://revbeergoggles.com/tb/tb.html
>
> Sprayed cleaner in it - would a dissassemble and thorough clean be
> more appropriate?
You wind up with a better job but it's not necessary. Sometimes I
take the idle air assembly off and dunk it in a glass of cleaner.
Just don't run the motor with the IAC out of its assembly. The
little pin will go shooting out and that's it for the stepper motor.
Should pick up a new gasket for the throttle body, since the old one
hardly ever seals back properly. That and it's cheap insurance in
case you rip the old one taking it out. And don't use a wrench on
the bolts, they only go in to 9 ft.lbs. That's easy to overdo with
just a screwdriver.
--
DougW
> "DougW" wrote
> About 2 years ago for the fuel filter.
> Did notice a crack in the boot coming off the pressure regulator to
> the manifold - did a temporary fix with electrical tape.
> When the engine does start there is a noticable gas smell - would a
> bad regulator show these symptoms?
Yes, if the internal diaphragm has broken it could be leaking and that
leak will run back into the intake. Easy enough to tell by simply
removing the vac line while the engine is running, and checking for gas.
So can leaky O-rings in the fuel rail quick connectors or leaking
injectors and their pressure side O-rings. Easiest way to check is to
wipe the rail and injectors down, run the engine, then go back with some
kleenex and see if you can pick up any fuel. Injectors can leak around
the electrical connection. If they are then they have to be replaced.
It is not necissary to replace them as a set, you can replace just one.
>> Engine RPM of 500-600 is normal. Have you cleaned out the throttle
>> body and idle air passage? http://revbeergoggles.com/tb/tb.html
>
> Sprayed cleaner in it - would a dissassemble and thorough clean be
> more appropriate?
You wind up with a better job but it's not necessary. Sometimes I
take the idle air assembly off and dunk it in a glass of cleaner.
Just don't run the motor with the IAC out of its assembly. The
little pin will go shooting out and that's it for the stepper motor.
Should pick up a new gasket for the throttle body, since the old one
hardly ever seals back properly. That and it's cheap insurance in
case you rip the old one taking it out. And don't use a wrench on
the bolts, they only go in to 9 ft.lbs. That's easy to overdo with
just a screwdriver.
--
DougW