Jchilly

There are several post out there that are close, but none really match mine.

So here it goes, I have a 2001 Cherokee 4.0L 4 x4. All of a sudden it started dying at idle. I have full power and no hesitation, it's just at idle it dies. So the first thing I changed was IAC idle air control valve...and nothing. Then I proceeded to change the MAP sensor, and then the TP sensor... And again no success. In fact now it will either do the straight up stall, or hiccup. And when I say hiccup I mean, it acts like it is going to stall (RPMs drop to zero and oil pressure gauge drops then it fires back up). Is if I turned it off then, turned it back on, minus the starter. Then it finally kicked a code. P1899 (Transmission Range Sensor) and according to my reader the 2 most likely fixes were the park neutral safety switch or PCM. So I then ordered a new PCM. I put the new PCM in and it ran fine for two days... Then it kicked code P1297 (No Change in MAP from Start to Run). Then It started kicking code P0340 (No camshaft Reference Signal at PCM) Thats when I decided to change the Crankshaft sensor, and the Camshaft position sensor. Only rather than just do the cam sensor I replaced the whole synchronizer just to be safe, and it was $20 cheeper than just the sensor. Anyway still no help, it still keeps stalling and hiccuping and it still keeps kicking code P0340 no camshaft reference signal at PCM. Other codes it has kicked are P1296 No 5 voltage to MAP, P1297 No change in MAP from start to run, and P1495 Leak Detection Pump Solenoid. The last one was real weird because just after kicking the code, my door locks cycled lock un-lock for about 30 seconds??? Im at a loss!!! Other things I have tried are cleaning all the ground wires and battery terminals. I also unplugged the PCM and all the sensors. Traced the wires back to the pins on the PCM plugs, then ran current through them and tested with a multi meter while shaking the harness/plugs to see if there were any shorts. I did that with each wire. For example the orange wire that runs from the cam to crank to PCM. I tested it all three ways. I have just sent the PCM back to be tested, but is there ANYTHING else anyone can think of I haven't yet tried, because Im at a loss!!!

Dark Angel

I'm not anywhere near an expert, I come here to learn, but my '93 Jeep Cherokee was having the same problem not too long ago. My Jeep was stalling at idle, and also when I would hit the gas after sitting at a red light or stop sign, it would sort of "cough" or stall and then take off just fine. Never had a stall at freeway speeds.
When I posted about it, the advice I got was to get a can of Throttle Body spray and clean out the Throttle Body. I took it all apart and cleaned it up really well, then put it all back together and my Jeep hasn't had a stalling problem since.

DFlintstone

MMMM, Comparing your Jeep to mine might be a little like comparing the Merrimack to the Titanic!

I had this deal with my idle, it would cycle about every 20 seconds. It would be even and fine for a bit, slow to nearly a stall, catch it's self and speed up for two secs, then even out and repeat. After I changed my 02 sensor it quit doing that. Just last week a guy with an old Renix Jeep like mine posted his idle was doing that. He took advise to change his 02 sensor, and BINGO, it cleared up.

No idea if just nearly stalling would make yours throw codes, does seems plausible your sensors might send odd info in that condition though.

I gather just leaving your battery disconnected overnight is an easy, safe way to clear your computers memory.

(no argument with cleaning the TB). Hopefully someone with experience with your 2000 will have something....

tjwalker

I suggest you contact your local church and schedule an exorcism....!!!

I'll think about this one for a while. But the fact that you have a myriad of codes makes me not believe any of them.

Just to be sure that you are delivering proper juice to every part of your vehicle, I'd have your battery "load tested" or try temporarily swapping in a different battery in there.

Jchilly

Thanks for the feed back. Isis throughly clean the throttle body before I put the IAC, MAP and TP sensors on there. As far as connections. I have a new red top optima 4 months old and new cables. I have also since the problem started, gone through and cleaned every ground connection under the hood. I'm starting to think the exorcism might be a good idea. Lol. Actually I'd like to know more about the O2 sensors. Do they normally send a code? And I have 4 of them 2 before and 2 after the cat. Anyone know a good way to check them? I already got enough into it, I don't wanna have to get 4 O2's if only one is bad.

DFlintstone

I'm completely out of my league here. I'm pretty sure it would show a code if the "sensor feed" or 02 heater circuits had a problem.I'm pretty confident the "post Cat" sensor on 91>99 doesn't affect operation. I think your post cat's do though, but I don't really know.

I haven't read this through to the end in a while, testing them is not at all simple, in any case> http://www.naxja.org/forum/showthrea...ht=sensor+test

Like I mentioned above, "plausibly" I suppose if they caused bad operation it might make it throw other codes, like missing, or even that speed sensor deal.

So I'm no real help. Was me I'd leave the battery disconnected overnight, and dance backwards around the Jeep three times!