'95 XJ 4.0 Stalling Issue

Been a while since I've been on the site, but we got my wife a 144k '95 XJ SE 4.0 AW-4 231 last week and I am in need of some help. I have been reading through threads non-stop for the last two days and feel like I am beating a dead horse, but I am trying to get this figured out quickly since we are down to one car.

She drove it all week and everything seemed fine. Then, on Monday, she was driving home from work and it stalled twice on her. Luckily it fired up and she made it home. Wanting to see the problem myself, we decided to take it to a friends place when I got out of work. We weren't even out of the neighborhood yet and it stalled. No CEL, no warning. To add injury to insult, it wouldn't restart either. So, we left it for 2 1/2 hours and, when we came back for it, it fired right up and went back in my garage.

Tuesday was my day off, so I figured I would monkey with it some. I got up and ran some Seafoam through the intake as per the can instructions and checked out some connections. Nothing seemed visibly messed up, so we tried to take it to the bmv just down the road. When I got it up to ~45mph and let off the throttle to hold that speed, it started to cut out and come back to life. It stayed running as I slowed down for the stop light, but as we waited for the light, it died. This time it fired right back up. So I turned the corner and it seemed ok until I went to turn right a 1/2 mile later. As I let off the gas to slow for the corner, it died again. So I coasted to the side of the road and tried to start it again. No dice. Came back an hour later and still wouldn't start, so I had it towed home. Later in the day it would fire back up, but, when I let it idle, it would randomly die. It was never a rough stall either, so this led me to believe it wasn't getting spark.

I turned the key and the fuel pump fired up like normal. I pushed the valve on the rail, and fuel came squirting out. This seemed to reinforce my belief that it was spark related. Everything I read pointed to CPS, so I changed it first. No difference. Then I thought maybe it was the IAC or TPS. Cleaned the throttle body and the sensors with TB cleaner (it was filthy); no change. After that, I changed the distributor cap since it is cheap; no change. Next on my list are O2 sensor, coil, or alternator. I don't think it is the alternator since it seems to be charging the battery (dated 7/12) fine. I don't think it is the O2 sensor since I am not getting a CEL. I suppose it could be the coil?

I really don't want to just keep throwing parts at it since it is expensive and time consuming. On the other hand, I can't really test it since it is so random. I feel like I have no choice in the matter but to keep replacing stuff. What say you, the great minds of ?

What was the brand and source of the new crank position sensor?

I've had the TPS (Throttle Position Sensor) cause random havoc, including stalling, unintended acceleration, and funky transmission shifting. I've also had a Cam Position (or Angle) Sensor cause sudden death. As the miles and years pile up, any sensor, connector or ground connection should be suspect. And, a '95, being OBD I, may not necessarily set a malfunction code. Most of the time, the bad TPS in my '96 (OBD II) didn't set a code. It set a code just the first time, and every time it acted up afterwards (I'm on the fifth one), it didn't light the CEL. Good luck, you're about to embark on a wild goose chase!

You mention cleaning the throttle body. Did you remove it, and if so, did you remove the IAC chamber from the side of it? The orifice that the IAC pintle seats against and the passages within are where you'll find the biggest collection of gunk. Be careful removing the chamber and you'll be able to save the gasket.

Well, I feel really stupid. My wife put gas in the XJ last weekend and apparently did something silly with the gas cap. I took it off and put it back on last night. Drove it for about a half hour and nothing odd happened.

:doh:

A gas cap not seated properly really should not create the symptoms you described.

I think they may return.

I recently had a similar issue where the Jeep would run fine then stumble and die. It would not start immediately after stalling. I would let it sit for a few hours and it would fire back up and run ok for a few minutes, then it would stumble and stall again. I thought it was the CPS, so I replaced it and it did not help. Today, I broke out the voltmeter and determined it was my coil. Replaced the coil and it runs great...