01 cranks but no start until holding gas pedal
12-11-2015, 03:38 PM
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Model: Cherokee
01 cranks but no start until holding gas pedal
Went to leave work today all the sudden jeep wont start cranks sounds like a few cylinders fire
I figure i would try holding the pedal down then boom starts let off the pedal all the way no idle just slowly dies out
Drove home by not taking my foot off the gas used two feet other to use the brakes
Got home idled fine ran like normal turned off waited a little started right up.
Fuel pump?????
They are $200 so dont wanna "try" that and it being something else
Thank you for any help anyone can give
I figure i would try holding the pedal down then boom starts let off the pedal all the way no idle just slowly dies out
Drove home by not taking my foot off the gas used two feet other to use the brakes
Got home idled fine ran like normal turned off waited a little started right up.
Fuel pump?????
They are $200 so dont wanna "try" that and it being something else
Thank you for any help anyone can give
12-11-2015, 05:11 PM
#3
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Year: 1999
Model: Cherokee
Engine: 4.0
Suspect #1 is a marginal battery. If available voltage is low, it gives the engine management system fits and the primary symptom is stalling at idle.
After the vehicle runs a bit and the alternator does its thing of charging the marginal battery a bit, it has enough juice to satisfy the engine management system and the symptoms go away. Sound familiar? How old is your battery?
Yes there are other possibilities. But you must rule the battery in or out before moving onto them. Have it "load tested". Any parts store will do this for you for free.
Good luck and keep us updated!
After the vehicle runs a bit and the alternator does its thing of charging the marginal battery a bit, it has enough juice to satisfy the engine management system and the symptoms go away. Sound familiar? How old is your battery?
Yes there are other possibilities. But you must rule the battery in or out before moving onto them. Have it "load tested". Any parts store will do this for you for free.
Good luck and keep us updated!
12-11-2015, 07:29 PM
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Suspect #1 is a marginal battery. If available voltage is low, it gives the engine management system fits and the primary symptom is stalling at idle. After the vehicle runs a bit and the alternator does its thing of charging the marginal battery a bit, it has enough juice to satisfy the engine management system and the symptoms go away. Sound familiar? How old is your battery? Yes there are other possibilities. But you must rule the battery in or out before moving onto them. Have it "load tested". Any parts store will do this for you for free. Good luck and keep us updated!
And get a fuel pressure tester
12-12-2015, 12:44 PM
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Two load tests from two different places both say bad battery now the jeep starts right up but rough idles at start only then goes away gonna get another battery and see what happens
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12-13-2015, 04:52 PM
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It was **** driving home multiple misfires flashing check engine light going up hill hitting throttle choppy as **** got home replaced tps started fine drove around for about 15 minutes drove fine came back turned it off waited about five minutes started it up started doing it multiple misfiring flashing light choppy and when you let off the throttle feels like a huge power loss
12-13-2015, 05:32 PM
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Year: 1999
Model: Cherokee
Engine: 4.0
Please post the EXACT codes you pull from the computer. Gotta use those codes as a roadmap to the root cause.
As for the battery, if it failed two load tests, that was money well spent as you were going to need one soon anyways.
As for the battery, if it failed two load tests, that was money well spent as you were going to need one soon anyways.
12-13-2015, 05:39 PM
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P456 small evap
However definitely multiple misfire after i left autozone where i got the scan ran like crap and got worse
12-13-2015, 05:44 PM
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Year: 1999
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I'd concentrate on that P0304. I don't think that the P0456 is the main culprit here.
1. Simple stuff first. When was the last time spark plugs were changed? New NGK plugs gapped to .035 if it's been a while would be a good idea.
2. Gotta ask. Have you been using any coolant? The 00/01 have the infamous 0331 cylinder head and if it cracks, will lead to coolant loss and possible misfires on cylinders 3 and or 4.
3. Getting a fuel pressure reading never a bad idea. Spec for the 01 is 49 psi, plus or minus 5 psi.
1. Simple stuff first. When was the last time spark plugs were changed? New NGK plugs gapped to .035 if it's been a while would be a good idea.
2. Gotta ask. Have you been using any coolant? The 00/01 have the infamous 0331 cylinder head and if it cracks, will lead to coolant loss and possible misfires on cylinders 3 and or 4.
3. Getting a fuel pressure reading never a bad idea. Spec for the 01 is 49 psi, plus or minus 5 psi.
12-13-2015, 06:15 PM
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I'd concentrate on that P0304. I don't think that the P0456 is the main culprit here. 1. Simple stuff first. When was the last time spark plugs were changed? New NGK plugs gapped to .035 if it's been a while would be a good idea. 2. Gotta ask. Have you been using any coolant? The 00/01 have the infamous 0331 cylinder head and if it cracks, will lead to coolant loss and possible misfires on cylinders 3 and or 4. 3. Getting a fuel pressure reading never a bad idea. Spec for the 01 is 49 psi, plus or minus 5 psi.
Coolant recently flushed after water pump replaced as close to 50/50 as i could be
Fuel pressure is getting tested tomorrow
12-14-2015, 11:57 AM
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Year: 1999
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1. If you are getting codes for the TPS circuit, you likely have a problem with it. OBD isn't perfect, but it's pretty good at pointing you to an offending circuit. Either the sensor, connector or wiring. I know you replaced the TPS. What brand sensor did you use? I've had very poor luck with aftermarket TPS sensors for the XJ. Were you getting TPS codes BEFORE you replaced your TPS? Or just after installation?
2. Have you had to add coolant to the coolant reservoir recently? Can't ignore the possibility of a cracked 0331 head here as that is what your 01 came with from the factory. If that happens, misfires can begin to occur in cylinders 3 or 4. Usually don't see the misfire early after a typical 0331 head fail, but they definitely can occur.
2. Have you had to add coolant to the coolant reservoir recently? Can't ignore the possibility of a cracked 0331 head here as that is what your 01 came with from the factory. If that happens, misfires can begin to occur in cylinders 3 or 4. Usually don't see the misfire early after a typical 0331 head fail, but they definitely can occur.
Last edited by tjwalker; 12-14-2015 at 11:59 AM.
12-14-2015, 03:43 PM
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1. If you are getting codes for the TPS circuit, you likely have a problem with it. OBD isn't perfect, but it's pretty good at pointing you to an offending circuit. Either the sensor, connector or wiring. I know you replaced the TPS. What brand sensor did you use? I've had very poor luck with aftermarket TPS sensors for the XJ. Were you getting TPS codes BEFORE you replaced your TPS? Or just after installation? 2. Have you had to add coolant to the coolant reservoir recently? Can't ignore the possibility of a cracked 0331 head here as that is what your 01 came with from the factory. If that happens, misfires can begin to occur in cylinders 3 or 4. Usually don't see the misfire early after a typical 0331 head fail, but they definitely can occur.
No tps codes before swap duralast tps i replaced the replacement one of the two codes are gone
I was also told platinum spark plugs are bad on jeeps and can lead to misfiring overtime so I replace them with copper spark plugs no more mess fire looks like for now however
Still throw one code P0122
Low input voltage tps wires look fine however a little stiff