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Topic
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I have had a problem with my ZJ now since atleast february this year that i cant figure out.
The problem is that sometimes it will not hold idle at all, it just dies unless i keep my foot on the gas to keep it alive.
It dosent matter if its warm or cold outside.There are some things i have noticed about the problem.
1: if the sun has been shining on it during most of the day the engine will to 99% idle just fine sometimes just a little low.
2: if its raining and i go out and start it after the rain has stopped it will not idle.When it dont have idle and i have to hold my foot on the gas to keep it alive the idle will return after the tempgauge is at around 90+c (normal operating temp) but it will idle extremely low, the tach barley shows it at around 200rpms..
If i then stop and turn off the engine and restarts it after a while it will first go up to about 1200rpms for a split second, then drop to 0 and stumble back up to maybe 500rpms.
It feels and sound like its going to die but saves itself.Things i have replaced:
Throttle position sensor
Idle air control valve
Intake air temp sensor
Coolant temp sensor
Map sensor
Battery
Cap and rotor
sparkplugs
Ignitioncoil
Checked for vacuum leaks by spraying starting fluid on the lines and there are no leaks.
Checked the wiring between the pcm and every sensor that is in the engine bay and its fine.Things i know are wrong and has been since before this all started
Small exhaust leak at the EGR tube where it sits on the right side manifold.
Plenum gasket is bad and burning 1qt of oil every 6000miles.
Hose from PCV valve to intake manifold is slightly cracked at the manifold and “fixed” with electrical tape.I had to replace the fuelpump 2-3 weeks before the idle problems started.
It never stores any codes when it happends
Anyone here have an idea of what i should check next?
Because i have run out of ideas.
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Replies
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It might be a good idea to change the fuel filter and if that does not help, check the fuel pressure.
It might not hurt to replace the sparkplug wires if they are in poor condition.
Could it really be something that simple?
Going to get a new one and replace it.
Now when i think about it i never did replace the filter after the old pump died.The ignitionwires are maybee a year old so they are probably fine.
Ignition wires can be easily tested. When its completely dark outside just start the car and pop the hood. If the wires are bad you could see the spark going to the plugs, especially if there are places where the wires touch metal.
Well a new fuelfilter did made it idle fine at start up for 2 days, now its the same again.
I am going to see if i can find a fuelpressuretester to see what the pump does when the idle is gone.I found this article regarding fuel issues in the Cherokee 5.2L – http://www.underhoodservice.com/tech-feature-jeep-fuel-problems-needn-t-be-an-uphill-battle/
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