jckevns

today as i was driving around, i was sitting at a stop light and my jeep just stalled. put it in park and it started right up, later on the same thing happened again.

i did the 703 injector swap about a week ago I haven't had any problems till today

it's a 93 4.0 HO

any ideas?

tjwalker

What you describe can happen when the crankshaft position sensor is starting to fail. It is a VERY common failure on the Jeep 4.0 engine.

When the engine loses the crank signal, you won't have spark and you wont' have fuel going TO the fuel injectors.

RB89XJ

I am having a similar issue in my jeep. I have an 89 4.0L. I had the IAC valve replaced not too long ago, and that fixed it for a while. Then it quit out on me and it would crank and but not start. I had the throttle body cleaned, and a new crank sensor installed. It starts now, but is giving me a the same stalling problem. I had all the vacuum lines checked and they are fine. My resting idle is about 500. I am wondering if the jeep is idling improperly, and that is causing it to stall out. I also have an emissions mat light on, so i was also wondering if that may have something to do with the issue. Maybe O2 sensor, CAT Conv, or something else?? Any ideas????