I have a 2000 Jeep Grand Cherokee Loredo. I just replaced all 6 plugs and put it back together. Everything fit back just fine and tightened down fine.

Now the vehicle will start but there is no idle. Sometimes it will idle for a couple seconds then shut off. If I give it some gas it will stay on a bit longer but will still shut off fairly quickly.

I removed the coil pack and reseated. All spark plugs are gapped correctly. I left the battery unplugged for about an hour in the hopes that a computer reset would help. The plugs are Autolite Platinum.

No luck.. any thoughts? Any reply would be greatly greatly appreciated.

Start the engine and keep your foot on the gas at 1500rpm for a few minutes until the engine will idle on its own.

thanks for the reply.

That doesn't work unfortunately. Even if keep my foot on the gas, it eventually dies as well.

Check your cables, turn it on and if you can wiggle each cable one by one, if you hear it bog out on a certain one that might be the source.

when it runs ,does it run good or bad?

This vehicle has a coil pack instead of spark plug wires. So wiggling the wires won't work

When it does start, it does NOT run smooth at all.

You sure all of the plug boots are seated on the plugs and not wedged behind the plug?

check the pcm

I did reseat it once already, but it was getting dark. That is something I'll be doing today. I didn't realize that they boots could get wedged behind the plugs.. I'll be sure watch out for that.. Thanks!


As for the PCM. All I've done is leave the battery unplugged in hopes that it would reset.

Maybe you knocked off or cracked a vacuum line?

I thought about that too, but was unable to find any leaks.

After more digging, i did come across a thread with similar symptoms. The guy had the same engine and he had similar symptoms after putting in AutoLite Plugs.

Everyone in the thread was advising to replace them with Champion plugs and that autolite had issues with that engine setup. So he replaced them with Champion and they run perfect now.

So that is the next thing I'm going to do is pick up a set of Champion plugs on my way home for work. *fingers crossed*

Problem Solved.


I removed the Autolite Platinums and replaced them with Champion plugs and the vehicle started right up.

So strange. I quadrupled checked and those are the right type plugs in the Autolite line for this vehicle, but who knows.

Thanks for the help guys!

Thanks for thread, now I know not to buy Autolites!

Ok I'm having the same problem with my 2000 Jeep Cherokee..... put in Autolites and now it only stays started for a minute then shuts off.

I keep telling you guys!

AC's in GM
Champs in Mopars
Autolites in FORDS!

I had the same problem in an old Dodge K-car. The ***** just refused to run.
I know if you run Champions in a Chevy, you have to go one heat range colder because of the extended nose. I knew some guys that had good luck with NGKs, but I never tried them.