Tim9368

Howdy All!

I’ve posted here before about this same problem, and have gone back to read numerous threads. Here is the scoop:
1993 Cherokee Country 4.0
243K miles
Auto 2wd

This is my teenage son’s daily ride.

We have had random stall and random no- start issues for a while. My previous thread: https://www.cherokeeforum.com/f2/intermittant-stalling-now-no-start-81836/



I have done the following:
· Completely cleaned the throttle body
· Changed fuel filter
· Replaced IAC
· Replaced TPS
· Checked coolant temp sensor with multi-meter against specs in Haynes manual
· Checked coil with multi-meter against specs in Haynes manual
· Checked CPS with multi-meter against specs in Haynes manual
· Checked ballast resistor with multi meter (good) and refreshed the wire connectors
· Checked all vacuum lines (good)
· Battery reads 12.7 volts (multi-meter) when engine is off – terminals and wires are clean

When the car runs, it sounds and feels fine. We recently went 2 weeks with no symptoms and then I had to go get him from a friend’s because it would crank and crank and no start. Next day I tried – same thing. On a hunch, I jump started it and we were off to the races. It stalled on me once on the way home (about 2 miles) but then I let it sit at idle for about an hour with no problem.

It occurred to me that his driving patters rarely have him drive more than 2 miles at a time, and sometimes just for /12 mile or so. Could this whole deal just be a battery that is not getting properly charged?

Thanks in advance for your help…

99 Purple XJ

I would look at replacing the CPS not just cleaning it

Tim9368

I did not clean it - I checked the wires, made sure it was not loose and then checked the resistance according to suggestions in another post (Both when it was/was not acting up) - It checked out normal both times. I don't want to replace parts that are not bad - do you know of any other way to be sure that it is/is not a CPS issue? I have had some of the classic symptoms, but not all...

a737mech

have u had the alternator checked sounds to me it is starting to fail it will somtimes fail to charge battery properly then one day bamb nothing batt. dead and no start jump battery she fires right up then bamb dead agian i would have alternator checked at autozone!

Tim9368

UPDATE:
I just drove the posessed beast to Advance to have them load test the battery and alternator. She fired right up, and stalled 3x on my way to the shop (<1 Mile) He hooked up the equipment, battery is good, alternator is good - it stalled 2x while we were running those tests. I still have no Fuel pressure test (he would not give me a loaner and the tool is about $50)

I did get a new code, however...

OBDI code 11 (same as OBDII P0320) = No Crank Reference Signal at PCM

Now I seem to think that it is definitely the CPS, but would love to have confirmation before buying another sensor...

Please let me know what you know!


Thanks in advance,

-t

Tim9368

I just finished with the fuel pressure test.
As soon as I start her up, it jumps to 32 psi. When I disconnect the vacuum line to the pressure regulator, it jumps to 41 psi. Specs in the Haynes manual say 31/39 psi respectively, so I think it is all ok there.

Also, when I just turn on the ignition, but do not start the car, it immediately jumped to ~40 psi and then slowly drainewd down to nothing over just a few minutes. Haynes says something about a leak-down test, and that this system should be under constant pressure. Can anybody shed some light on this?

Tim9368

Take a look at the pics - I pulled the old CPS and can see the bare wire where the insulation had been rubbed/burned off. Before installing the new one, I wrapped bothe ends of the wire with self-vulcanizing rubber tape. Hopefully, I'll get another 200K+ miles out of this one. Turns out it was just bad luck that several things were acting up at the same time, which made it more difficult to isolate this gremlin.

i gave it a good hard test drive, and it never even hinted at a rough idle or stall.