Gran Prix Missing at hig RPM

Did it have this problem before changing the plugs?

Rev limiter typically kicks in at 4k.

When in P or N it does. When driving it goes to 6K or whatever the redline is.

No the problem was not happening before replacing the spark plugs and wires. I just finished replacing both the wires and spark plugs again with no luck. Now the car is missing almost all the time but if it is park and i rev it up to 4k it is noticeably worse. Any suggestions? Thank you for your help.

With the car in the shade, and the engine running, mist around the wires with a spray bottle filled with slightly soapy water. You should find the misfire, if it is indeed ignition related. I'd suspect you cracked a coil tower and didn't notice.

It's also quite possible that you have picked up an injector misfire that just happened to happen on the same day as your tune-up parts installation.

GW

Sounds like something went wrong during the work. First of all check the wires for correct routing and make sure that the boots are seated properly. Could be faulty wires too. Did you verify plug gap? I once had a loss of power after changing plugs that turned out to be due to a broken insulator that sealed off the gap. It is possible that something was knocked off during the work. Try taking off the air filter off and see if the problem still is there.

Thanks for the help. I did try taking out the air filter, changed wires (found one was defective) and went ahead and bought new plugs as well... I am sure all of that is good now. I removed and instpected the coils but did not try to mist around them. Will try this today and post the outcome. Thanks again.

Have tried everything to isolate this problem. The car is much worse now with the missing at idle and almost impossible to drive.

Mist around wires with no luck. Removed air filter with no luck. Pulled and replaced spark plugs, verified gap. Replaced wires with no luck.

Any last suggestions before I bite the bullet and take the car to the shop? Thanks again for the help.

If I were you I'd take the, I forget the name of them, but I think that they're the coil packs or modules..whatever the wires snap onto that aren't the plugs..off and take them to be tested. If those are fine then go a little deeper and try that.

Double check firing order and plug gapping, im not sure on the gap size usually it is in the owner manual in the specs

I have a 99 Grand Prix with the 3.1 and it has a rev limiter around 4K that won't let it rev any higher. It kicks the the rpms down when you get that high

The Rev limiter will kick in if you rev up to 4k in _Park_. That's what you're hearing in this instance.

If the engine is missing when in Drive, that's another story.

I'd check for spark plug wire arcing by rev-ing the engine in a dark garage, and look for sparks. Hopefully it's just one wire having problems.

-cheers-