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  #1  
Old July 26th, 2005, 18:27
NitroDuck NitroDuck is offline
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Rough idle and dieing once engine is warm

Well my problem started Sunday, I was driving home from work and the jeep was doing fine, untill I rolled up to a stop light and the whole jeep felt like it was rocking, I looked down at my rpm gauge and it was borderline zero. So I gave it some gas to keep from cutting off. Well It never would cut off at lights the rest of the way home. So the next morning before work I and looked for any loose vacume lines because this has happened to me once before, but I saw none.

So running late I had to leave, about half way to work at one light it completely shut off, so I cranked it back up. Then one stop light away from work it shut off again, so I cranked it but this time it reved up around 2000 rpm and wouldnt go back down. So I pulled in the parking lot and turned it off, started it again and it still was reving around 2k.

After work I came out and it cranked up and was ideling fine untill it got hot then it stated rough again. So I stoped off at Auto Zone and got a new distributor cap and button and a new set of spark plugs. Changed these and it seemed to idle a little better. I went swimming and drove when I pulled into my grandfathers driveway it cut off again, so I recranked it and it shut off imedatly, also on the way home it was a pain to keep running, having to hold the break and gas (auto) at the same time.

Finaly once I got home it shut off again. So if anyone has any ideas I would be thankful.
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  #2  
Old July 26th, 2005, 19:10
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langer1 langer1 is offline
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Re: Rough idle and dieing once engine is warm

I could be lots of thing accept a cap and rotor.
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  #3  
Old July 26th, 2005, 19:26
NitroDuck NitroDuck is offline
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Re: Rough idle and dieing once engine is warm

Quote:
Originally Posted by langer1
I could be lots of thing accept a cap and rotor.
Yeah, I realize that. Thus the reason why I am asking for help.
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  #4  
Old July 26th, 2005, 19:51
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8Mud 8Mud is offline
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Re: Rough idle and dieing once engine is warm

Stalling at a stop or a slow speed corner, has been a stuck open EGR for me in the past. But that doesn't account for the 2000 RPM Idle.
A sticky IAC will do what you discribed. Even give you a really high idle, but I donīt really know if it will idle to 2000 stuck full open. Possible, but I really canīt say for sure. Might want to check for a stuck throttle at the TB, a few drops of lube, sure isnīt gonna hurt anything.
Pretty easy to clean the IAC piston and the seat, Iīve gotten in the habit of putting a drop of synthetic motor oil, beside the piston so it runs around it and into the backside (piston rod and motor). Pulling on the piston can pull the whole thing out of the IAC. There is a threaded, greased rod hooked to the back of the IAC piston. Usually when they stick, it is a buildup between the piston and the well walls, when trying to clean this buildup off, try to pull it out, instead of pushing it in behind the piston (solvent probably isnīt a good idea).
I really canīt think of much that would cause a sustained 2000 RPM idle, except a stuck open throttle (or bad return spring), a stuck open IAC (maybe), multiple vacuum lines disconnected (the biggest vacuum line will often give a 1500 RPM idle when disconnected), or a bad TPS (ECU side).
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  #5  
Old July 26th, 2005, 19:56
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langer1 langer1 is offline
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Re: Rough idle and dieing once engine is warm

Will let start with year and engine, what kind of test equiepment go you have?

You will be given thing to test so you will need the stuff to do the tests.
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  #6  
Old July 26th, 2005, 20:47
NitroDuck NitroDuck is offline
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Re: Rough idle and dieing once engine is warm

Sorry its an 89 inline 6.

Test equipment would have to be my hands, eyes and ears.
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  #7  
Old July 29th, 2005, 08:09
lenny lenny is offline
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Re: Rough idle and dieing once engine is warm

Hi
sorry to hear that your having the same problem as I am!!! I have a 89 4.0 4x4 also
check that tps is what I was told if it got stuck in high idle. now i dont know what the test could be.
Ive only had that problem once.
My problem now is rough idle after shut down and then try to restart-up. Sounds and feels like I moved the spark plug wires around.
Yesterday i was told i need to check when this happens again, see if its ele or fuel! So i have a spear spark plug, with me all the time.
Then disconnect one wire and plug the spear plug into it and try to see if you have any spark. but you would need help to turn the power on.
Also there is a bank of relays just near your battery try and switch the 2nd relay with the 4 relay if it starts then you will be knowing that maybe the relay you removed may be hanging up.

Now the next thing I told to have the rack checked to be sure its under correct pressure in that line. You now know that its ok with a normale start.

Then my idea is that you should check, I belive the fuel rack when this happens again, to see if it could get a vapor lock! I belive you could check by doing this.
There is a valve like a tire stem valve, take the cap off and press the valve but DON"T do it looking into the valve because your would be covered in fuel do it from the front of you truck and wearing safty glasses!
Fuel should come out at a steady flow maybe as far as 3 to 4 feet!!! then it should be ok.
If you notice that it isnt a good flow then Im wrong.
If it isnt a good flow I thinking its getting a vapor lock.
Then Im thinking that if you jump in and start your engine and press the valve again but I would think you want to do this fast.
If it you could have a helper would. I think if there is a vapor lock u could bleed it out with someone trying to keep it running.
START AND MOVE FAST PRESS again being very careful were you stand!
If this works there should be a way to stop this, but I havent found that out yet!

Now this is just my idea about the vapor lock. Maybe others here could give feedback about this idea of a vapor lock. I'm hoping someone would give me advice or tell me this is a good idea or not!!
good luck and if i should have a rough start again I will tell you how my testing has gone!!
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  #8  
Old July 29th, 2005, 08:13
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langer1 langer1 is offline
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Re: Rough idle and dieing once engine is warm

You don't get vapor lock on a fuel injected engine, so that's out.
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  #9  
Old July 29th, 2005, 20:49
lenny lenny is offline
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Re: Rough idle and dieing once engine is warm

Hi I just found this someone told to to look for it!
thanks to that person!!

I felt It should be moved up here so others would find it!
many thanks to the person that did post this!!!
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Sparkman
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Re: XJ misses out after it warms up on restart

--------------------------------------------------------------------------------

Fuel System - Hot Start Misfire/MIL ON/DTC's/Rough Idle
NUMBER: 18-031-03

SYMPTOM/CONDITION:

Customers may describe a 20 to 30 second rough idle following the restart of a heat soaked engine. This condition may be most noticeable when the engine is restarted following a prior 10 to 20 minute heat soak in hot ambient conditions of approximately 32°C (90°F) or higher. This condition may be consistent with short city stop-and-go driving trips and can be aggravated by the use of fuel with a high ethanol content. Depending upon various conditions a MIL may occur due to DTC P0303 - Cylinder # 3 Misfire.

This condition may be caused by heat from the exhaust manifold that following engine shut down migrates to the area around injector # 3 and causes fuel vapor to form within the injector. This in turn may cause a momentary misfire of cylinder # 3 until the fuel vapor is cleared of injector # 3. The insulator sleeve lowers the injector # 3 temperature to a point below which the fuel will not normally vaporize.

REPAIR PROCEDURE:
1. Cut insulator sleeve, p/n 56028371AA, to make two (2) insulator sleeves about 25-30 mm (1 in.) in length.

2. Install one sleeve around injector # 3, with the slit on the upward facing side of the injector. Install the other sleeve with the slit on the downward facing side of the injector.

3. Confirm sleeve is flush to intake manifold surface around injector.

4. Check injector # 3 wire and ensure that the injector is rotated to a 2 o'clock position (from driver's side of vehicle).
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  #10  
Old July 29th, 2005, 21:39
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mrbill3 mrbill3 is offline
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Re: Rough idle and dieing once engine is warm

Quote:
Originally Posted by 8Mud
A sticky IAC will do what you discribed. Even give you a really high idle, but I donīt really know if it will idle to 2000 stuck full open. Possible, but I really canīt say for sure. .
I'll side with 8mud. I would bet your IAC is bad. Had the same problem with my 89 XJ 4.0 I6 back in May. I had had the problem on and off for about 9 months, but it started happening more frequently in May. I replaced the IAC (Neihoff Part #21771 From Kragen/Checker/Parts America.com) Haven't had a problem since. About 3 months and 3K miles!
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  #11  
Old September 12th, 2005, 15:18
Biernuts Biernuts is offline
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Re: Rough idle and dieing once engine is warm

4. Check injector # 3 wire and ensure that the injector is rotated to a 2 o'clock position (from driver's side of vehicle).
-------------------------------------------------------------------

Does it really matter how the injector is positioned? I can rotate mine left to right while they are installed...could this be causing the problems that I am seeing which is also (slightly) rough idle but starts to run poorly, misfire and die once warmed up and under load...
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  #12  
Old September 13th, 2005, 16:26
Tom_W Tom_W is offline
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Re: Rough idle and dieing once engine is warm

Whoever it was a few posts up that you cant get vapor lock on a fuel injected engine, never drove a 280ZX. They have fans specifically to blow on the fuel rail, to prevent vapor lock (and if the fan doesnt work, you will find you have vapor lock the next time you go to start it)
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