Bad idle once again

1994 Jeep Grand LTD. 4.0L

I have replaced the IAC, Spark plugs, Fuel Pump, Fuel Filter, and Cleaned injectors but still my jeep idles rough but never stalls. Bad idle only happens then the jeep is in gear

Please Help :banghead:

Have you tried replacing the ignition coil or PCV valve?

I went throught the same thing. replaced iac,tps,maps, and it ended up being the coil. try replaceing that. mine was idleing rough and hesitating when I floored it. It was driving me nuts. after spending $$ on all of the above it ended up being a $30 coil. go figure

Doesn't the '94 have a cap and rotor? I'd replace those, as well as the spark plugs.

Thank you :grinyes:


I am going to get the coil fixed today


the 1994 jeep will live on

Was your coil the problem???

Also, (for anyone else out there) is there a good way to measure and see if a coil is just intermittent? I've done quite a few things to my 1996 JGC and I have a rough idle, hesitation and misfires (last recorded as 2, 5 and 6 but they bounce all over and I doubt it is mecahnical at this point) when I floor it as well.

The kicker is when I put a new IAC on it, it REALLY got low RPM in gear and stopped. I put the old IAC back in and it still idles rough, but better than the new one. Could the stalling with the new IAC be emphasizing the bad coil or pointing to a defective new IAC part?

So, should I take a stab at replacing or measuring the coil again. What brand of coil should I use. Does it have to be MOPAR or can someone recommend somethng else?

I have always suspected that I got a bad CPS, because it was the first thing that went bad, but I'm willing to look hard at the easy stuff first.

All other obvious "tune up" things have been done.

Thank you.

Bryan

well i had some free time so i changed the coil, jeep is now running smooth


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