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engine stalls

T

toughtread

NAXJA Forum User
Location
pinon hills, ca
I have an 89 with a 6L in it. i was driving down the road and the engine died. when i try to start the engine, it rns for about a second then dies. if i push the throttle while tyring to start it, then it acts very flooded and wont start at all
 
It may be a sticky IAC. When you try a restart just give a little pedal (maybe 1/8 pedal), too much pedal and you may flood it. If the B+ latch relay is bad, it can also do this. A very marginal battery can also cause IAC issues.

A stuck open EGR valve can do the same thing, less likely but it can happen.

Most of the trouble with the IAC first becomes noticeable when you release the gas pedal, if it is in fact stuck shut, it starves the engine of air. Take a look at your air filter and see if it isn't very oil soaked, some oil doesn't often mean much, a lot can cause grief.

Often a bad CPS and you won't get any start or sometimes when the engine heats up it will stall and may run really bad or not at all. CPS can be unpredictable.
 
mine drove me crazy. it just stalled out of the blue. no particular action provoked it and it turned out to not be the cks, but in fact the plug itself.
 
i checked the amount of air coming in the intake. it sucks so much air, seems like it will pull your hand right in. i also checked the amount of fuel coming in and it's flowing very well. the egr valve seems okay, is it posssible to check the cps for malfunction issues?
 
i checked the iac and it is good, just needed cleaning. if it helps my xj has the 6L, auto trans with 4x4. any throttle amount what so ever and the engine wont even start.
 
Here's how to check the CPS:
Renix CPS Testing and Adjusting
　
　
Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.
Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad.
The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.
Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.
You should get a reading of .5 AC volts.
If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.
Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.
A little trick for increasing the output of your CPS is to drill out it’s mounting holes with the first drill bit that just won’t fit through the original holes. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.
　
Revised 11-29-2011
 
been busy with 12 hourshifts at work. checked the above, no luck. i was told my xj has a "check engine" light on the dash. i cant seem to locate it. i checked the cluster on the left side of the dash, and it is not in that cluster ie brake, seatbelt, washer, etc. still checking, same problem.
 
okay, gettin a little closer. i ran a wire from the hot side of the battery directly to the ballast resister. the engine runs smooth and continous without shutting off. i'm checking the electrical diagram for possible trouble spots. any suggestions?
 
bypassing the resister nets the same. i think i tried that when i was stuck on the side of the road. figured it wouldnt hurt to try again in a more controlled environment.
 
additional information: i realize now that i should have advised this info sooner. the previous owner replaced the auxillary fan and did not use the handy little plug for the oem fan. he used the wire from the front tab on the resister for the power supply. i have minimal experience with resisters and am not aware of any issues this would cause, if any.
 
I unplugged the fan when the problem occurred and have not hooked it back up yet. I wondered if that was the source of the problem to begin with and plan on using the factory plug instead, just havnt hooked it up yet.
 
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