Hi everyone, so just like the title says. I will just be driving along, and my engine will momentarily turn off. If I am on the highway it cuts off and restarts itself. If I am sitting at a red light, it will cut out and I will have to restart it. It always restarts without a problem and is running great. My Jeep is a 1999 4.0 liter automatic four wheel drive with cruise and air conditioning. Could it be the fuel pump? Is there a sensor that could be failing? Could there be some weird relay that is going bad? I am not too sure where to start. Any help would be excellent!
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99 Cherokee engine randomly cuts off for a split second
- Thread starter outracing
- Start date
- Location
- Minneapolis, MN
The Crankshaft Position Sensor is the first thing to suspect. Crank Position Sensors can have intermittent “thermal failure”. This means that the CPS/CKP fails when the engine gets hot, but works again when it cools back down. You should test it, but it may only test bad when in failure mode.
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CPS Testing
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 the 10K-or-2OK scale for this test.
3. The meter reading should be open (infinite resistance). Replace sensor if a low resistance is indicated.
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CPS Testing
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 the 10K-or-2OK scale for this test.
3. The meter reading should be open (infinite resistance). Replace sensor if a low resistance is indicated.
Vernicious
NAXJA Forum User
- Location
- Layton, Utah
I had a 98 Euro XJ that used to do that. Now mine was a diesel, but the majority of the wiring is the same. There are tons of connections behind the dash that gave a tendency to overheat and lose conductivity. I'd check the easy stuff first, but if it continues you might want to look there...
Mine started like this and progressive got worse till it refused to start, I replaced the cps the IAC and the tps. You know what it turned out to be my brand new accel coil with less then 1500k on it died. Test the components don't be stupid and throw money at stuff like I did there are tons of guides online. Though replacing the cps is good maintenance hence why I was happy to do it and cleaning your iac is free too!
iluv83vettes
NAXJA Forum User
- Location
- Houston
Make sure to use Mopar sensors. I have spent more time and money wasted on parts store sensors that are bad out of the box than I can count.
Are you getting a CEL, and if so, what are the codes?
Are you getting a CEL, and if so, what are the codes?
Raine883
NAXJA Forum User
- Location
- East Texas
This is the truth, for some odd reason nobody seems to be able to build any engine management parts worth a damn outside mopar.
No check engine light. Today on my way into work I drove 6 miles at 60mph with no problem. As soon as I turned into the residential neighborhood and dropped to 30ish the Jeep died. It restarted 2 times but had to coast into the parking lot at work. If I can get it home, should I try the CPS next?
Well, I have two auto parts stores near me. I checked both of them and neither one sold Mopar brand crank position sensor. I ended up purchasing one from Autozone. It took about 20 minutes, but I got the crank position sensor replaced. I drove 60 miles so far so good. Fingers crossed, thanks for your help everyone.
- Location
- Southern Maryland
I would not trust autozone parts, get another while you still can
Last time I had that problem it was the coil
Last time I had that problem it was the coil
zouch!
NAXJA Forum User
- Location
- SF Bay Area, Calif
i had a problem like this once where it turned out to be a failure in the connector to the coil; one of the pins had broken loose in the housing, and would just intermittently decide to wiggle into a position where it wouldn't make contact anymore.
was a pain to find, since the wiggle-test would always seem to put it into place and cause it to work fine, but was pretty scary when it would decide to just die while driving along.
was a pain to find, since the wiggle-test would always seem to put it into place and cause it to work fine, but was pretty scary when it would decide to just die while driving along.
sidriptide
nobody of any consequence
- Location
- western massachusetts
sounds like your CPS fixed you, but i had a similar issue with a 98, except it wasnt stalling at idle.
it would randomly cut out just for a split second just enough to feel the stumble. and especially on right hand curves at speed. i dont know exactly where the issue was but it was a bad ground somewhere in the harness. after 4 trips to a local guy with years of Jeep experience, i got sick of paying him to chase a ghost...
i stripped the entire harness of all the tape and sheathing and in the engine compartment and cleaned scrubbed and resecured every ground i could find. you would be suprised how many there are.
one of those grounds was the problem, likely one of the ones under the ECM.
i chased it for 3 months and as soon as i felt i fixed it i sold it for beer money.... if i kept it it would surely come back, if i sold it, the problem would be gone forever.... i was right.
grounds do crazy shit..
it would randomly cut out just for a split second just enough to feel the stumble. and especially on right hand curves at speed. i dont know exactly where the issue was but it was a bad ground somewhere in the harness. after 4 trips to a local guy with years of Jeep experience, i got sick of paying him to chase a ghost...
i stripped the entire harness of all the tape and sheathing and in the engine compartment and cleaned scrubbed and resecured every ground i could find. you would be suprised how many there are.
one of those grounds was the problem, likely one of the ones under the ECM.
i chased it for 3 months and as soon as i felt i fixed it i sold it for beer money.... if i kept it it would surely come back, if i sold it, the problem would be gone forever.... i was right.
grounds do crazy shit..
