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No start after coil rail removal.

Ice RHD

NAXJA Forum User
Location
NH
My 2000 xj was starting but shutting off after a few seconds so we pulled off the coil pack rail. We found nothing wrong so put it back and now it won't start.

Seems to be coincidental. What did I do? We tested all we could think of but we didn't find anything. The Haynes manual wiring diagrams don't help much.

Any Ideas?
 
Test the Crankshaft Position Sensor. Put the Haynes in the outhouse, it will prove to be more useful there.


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CPS TESTING PROCEDURE 1991 – 2001 4.0L H.O. engines

1. Near the rear of intake manifold, disconnect sensor pigtail harness connector from main wiring harness.
2. Place an ohmmeter across terminals B and C (See Image). Ohmmeter should be set to 1K-to-1OK scale for this test.
3. The meter reading should be open (infinite resistance). Replace sensor if a low resistance is indicated.
 
Shouldn't a CPS failure throw an OBD-II code? My 2000 did when the CPS went bad...:dunno:
 
Shouldn't a CPS failure throw an OBD-II code? My 2000 did when the CPS went bad...:dunno:

Maybe, maybe not. On some CPS/CKP failures you will actually lose the ability to communicate with the OBDII port. "What we have here, is a failure to communicate!" RIP Strother Martin.

DIS testing: http://www.aa1car.com/library/dis.htm
 
What happened here? I'm having similar issues every since I changed plugs, my xj has not been running well at all.

Year, engine, the basics ALWAYS, please. And please don't tell us you put E3s in it.
 
2000 XJ 4.0 I tried NGKs and Champions and both do the same. I get sputtering and rough idle as well as some pretty harsh misses while accelerating. Sometimes when I start it up, it barely even runs at all until I fight to get it revved up enough to blow itself out. That only happens once in a while.
 
But after blowing it out it runs fine until you shut it down. Mostly on hot restarts, but sometimes cold?

If so, try this FREE, quick and dirty test: run it and get if fully warmed up. When you park and shut the engine down, open the hood and let it cool for 30 minutes before attempting a restart. If the symptoms are greatly reduced or gone, then you have heat soak. The 99-01 models are prone to this, there is a TSB on it but the factory fix is to insulate injector number 3--it seldom works.

Anyway, give it a try a couple of times and post up your results.

Good luck.
 
Intresting... I actually got an error code a while back that said something like cylinder #3 misfire. Thanks for the info. I'm guessing this is only part of the problem though. It still runs poorly otherwise. I'm actually considering buying a whole new coil rail. How can I know if my O2 sensors and crankshaft position sensors are okay or not? I have 4 O2s on my California emissions XJ. I'd hate to replace a perfectly good sensor, let alone 4 of them.
 
#1 check the gap on your sparkplugs,dont listen too ohh there gapped at the factory.Remeber they have to travel to get to the store. Try and loosen the bolts on your coilpack a little and line it up right, its a little tricky to do might take a couple of tries. good luck.
 
Ok, Jeeps been sitting for months. I charged the battery which is a under powered walmart 525 cca and the Jeeps starts and runs. But today I started it and let it warm up it ran good for 15 min then died and won't start. So I'm thinking it's a battery or an alternator issue. My plan is to buy a new battery then check the alternator.

What is the best way to test the alternator?
Start it then pull the negative cable and check for voltage drop?
Any other way?
 
Mega BUMP from OP

Please do not bump threads. Thanks.

Ok, Jeeps been sitting for months. I charged the battery which is a under powered walmart 525 cca and the Jeeps starts and runs. But today I started it and let it warm up it ran good for 15 min then died and won't start. So I'm thinking it's a battery or an alternator issue. My plan is to buy a new battery then check the alternator.

Or the CPS is shot. Given the symptoms and history of this problem, starting there sounds reasonable.

If you're buying a replacement CPS, I would strongly recommend biting the bullet and buying only an OEM one. Quality on the aftermarket ones has been horrible recently.

What is the best way to test the alternator?
Start it then pull the negative cable and check for voltage drop?
Any other way?

DO NOT DO THIS. The voltage regulator on a 2000-2001 XJ is built into the PCM; disconnecting the negative cable could have disastrous results.

Remove the alternator, take it to a shop that rebuilds alternators, have them bench-test it.
 
Ok I brought it to a shop where a former Chrysler tech. works. They changed the cam sensor. they are saying my jeep now has spark at the coils, signal from the crank sensor, cam sensor, but the ecu/pcm isn't triggering the sensors so it needs a new ecu/pcm. They said if they could borrow a known good one to check every thing that would work to. They quoted me $150 for a used ecu. I'm going to look for one over the weekend for less or to borrow one. It would be great if it was the ecu, but no one knows for sure. Just like the cam sensor they couldn't promise if that would fix it or not.

My budget is near exhausted for this project I needed this fixed two days ago and I don't have a lot of time to work on it. The garage will just keep using trial and error as long as I have the money for it, which I don't.
 
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