QuestionI have a 6 cyl TJ with 120,000 miles. I am the original owner. Without warning it will cough & sputter and loose power. When I pull off the road and let it sit a few minutes it will crank up and run fine until the next episode. I have changed coil, wires, plugs, catalytic converter, used gas additives, etc.. Was there any history of wiring problems associated with the 97 TJ? It reminds me of an electrical short. Nothing shows up on diagnostics. Thanks!
AnswerThat is a hard problem to diagnose because there may not be anything wrong except when the problem is evident. It could be as simple a as a bad ground, a sensor, or something internal.
Here is a few things to check.
Fuel pressure. Your pump may be getting worn and when it heats up, not putting out the pressure it should. If you can buy a gauge, connect it and drive so you can watch it. When it acts up, see where your fuel pressure is.
Throttle Position Sensor
IAC Sensor
MAP sensor
Double check your ground wires and connections. Grab ahold and tug good. Maybe even run a couple more! It can't ever hurt. Block to frame, trans to frame. Maybe new + & - battery cables if they look bad. One bad ground can cause lots of weird problems.
I had an 00 TJ auto, that the torqueconverter lockup would unlock and lock sporadically while driving. I finally figured it to be a bad ground and ran a new ground strap from the trans to the frame and it fixed the problem. Took me about a year to figure it out.
