jeep cutting out and dying for no reason....

1994 XJ 4.0 HO with codes 27 and 15.jeep runs at idle but almosy immediately stallls at throttle.this is my third 94 4.0 and have been around them for years but there is no reason for these codes from what i can see?bad pcm maybe?never had an issue with one yet.....

https://www.quadratec.com/jeep_knowledgebase/article-24.htm
Check there. I had 15 on mine until I replaced the speed sensor on the transfer case even though it worked most of the time.
27 is likely your reason if your injectors aren't working well as the code suggests.

well the speedo aint working but that shouldnt kill the engine.the injectors seem to be doing fine by the screwdriver click test......

But a TPS is part of the load detection along with MAP and IAT. If ones missing the thing won't run worth a damn


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blakews2217 said:

But a TPS is part of the load detection along with MAP and IAT. If ones missing the thing won't run worth a damn


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Click to expand...

Worn noisy spots on the TPS (test it with an analog volt meter for a smooth sweep), dirty IAT, clean it, bad Vacuum connection-line to the MAP. inspect it

http://mechanics.stackexchange.com/...code-27-with-engine-light-on-94-jeep-cherokee

But the code 27 sounds like a shorted injector, injector wires, bad PCM driver circuit on the ground

And thinking out loud, I would also check the CPS for grins and does the 94 have a sync signal from the dizzy????

And WTF is a "injectors seem to be doing fine by the screwdriver click test.":laugh3:

its when you put the shaft of a screwdriver on the injector and the handle to your ear to listen to the injector to make sure its firing.

ceasar said:

its when you put the shaft of a screwdriver on the injector and the handle to your ear to listen to the injector to make sure its firing.

Click to expand...

LOL. I would have never guessed it had that name, but it makes sense now.

ok.....i have been through this thing the last couple weeks....new....CPS,TPS,MAP,IAT,o2 sensor,checked every wire and vacuum hose on it and replaced a few vacuum just because they looked frail.the only code now is 27.....injector circuit isnt switching when its told.is this due to a relay? as i have checked every connection and everything seems fine and as i said i am hearing clicking at the injectors with the screwdriver test.jeep dies at about 120 degrees

Dies at 120 F? Coolant temp or Intake air temp?

At idle? or while driving or in park when you give it gas?

Does it die in park when you give it gas? If yes, what is the fuel pressure when you give it gas? So far it sounds like too little gas on acceleration, but I have too little info to conclude that.....

If it idles smooth I would not be inclined to suspect the PCM or Injectors right away.

You have done all the wiring harness wiggle tests right?

Is the Dizzy shaft bearing good?

Otherwise we may need to think on a deeper meaning for this:

"code now is 27.....injector circuit isnt switching when its told"

Can a bad PCM on some other part than the injector drivers do this. I say yes if the MAP sensor or TPS signal change data is not getting into the PCM like it should, thus wires or the PCM???

Code 27 and dies at 120 F? Hmmm

Two best guesses would be something in the distributor and/or a bad O2 sensor.

My 96 would die and/or stall and/or run really bad, as soon as it switched from open to closed loop. New O2 sensor cured that. Never did throw a O2 code until the O2 sensor was seriously dead.

Cross firing in the distributor will throw a 27 code. Like Mike mentioned a sloppy rotor shaft. Carbon scoring in the cap. Had one where the center contact in the cap fell out. Had another that had water under the sync sensor and would short as soon as the motor heated up, best guess is the water turned to vapor and only gave me grief when things heated up.

You may have more than one issue.

Just some guesses.

dies at 120 at every time at coolant reading on the gauge cluster.

doesnt matter....at idle at throttle or going down the road.hits that temp and dies.

idles fine until at 120 F.replaced PCM and checked injectors.

i have wiggled every wire and checked every damn vacuum hose in this thing:rattle:

i am not sure if the dist. bearing is good?havent gone that far but if it fires and idles without a miss why suspect that?

i am going to unplug the battery and wipe the codes again and start over.

i should say this situation started after a hard mud/crawl which broke off the 02 sensor and harness and destroyed the exhaust manifold.got it replaced and now i have this issue.....

Then you need to get it hot where it dies and use a meter to test the wiring harness itself for a temperature sensitive short.

Disconnect the O2 sensor and see that stops the problem is a good test of the sensor-wiring system. Same for the CTS sensor.

Test the CTS sensor itself when hot and cold. Is it bad when hot??? A hot air gun can be used to heat up sensors to see if they fail when hot.

You may mud in a place that is shorting things when it gets hot. Even the Alternator may be suspect from such a mud encounter, but I would test the wiring itself on the O2 sensor, as this is very suspect from the history and problem.

Is your elect fan still connected? Try unplugging it.

I know, what the heck does the fan have to do with it.

Dying at a fairly consistent temp is typically due to a failed component developing a short/open at that temp. Sounds like you've changed/tested most of them. However, the fan doesn't turn on until about that temp. Perhaps there's a short somewhere that connects once the fan switch closes. Check the relays. Simple test so easy to rule out.

That mud can get everywhere. Good Luck

its a manual so it has only a clutch fan.