97 GP misfire over 2300 RPM

[jph2424]

I need help.
I have a 1997 GP, auto trans, 3800 non-supercharged with 187,000 miles.
When I take off from a stop and get up to speed no problem, but when the trans shifts and the RPM's drop down below 2300 and then I give it a little more gas, the engine starts missing and shaking real bad. If the RPM go over 2300 and I give it gas, no problem. No misfire. If i'm on the expressway cruising at 60 MPH and give it some gas to pass someone, it will mis and sputter and shake unless I very gently push on the gas pedal.
I have changed the Maf and throttle control sensors but no help.
What could be causing this?
What should I try next?

[richtazz]

search the forums for "trans shudder" or "chuggle". There are multiple threads about this issue.

[BNaylor]

Oh yes, the old chuggle aka fishbite. The effect is the torque convertor clutch (TCC) locking/unlocking.

GM has a TSB out on this problem where it recommends checking out the throttle position sensor (TPS).

Also, in my experiences it can be caused by bad spark plugs and ignition wires. How old are they? And what brand?

[wlkjr]

Originally Posted by bnaylor

Oh yes, the old chuggle aka fishbite. The effect is the torque convertor clutch (TCC) locking/unlocking.

GM has a TSB out on this problem where it recommends checking out the throttle position sensor (TPS).

Also, in my experiences it can be caused by bad spark plugs and ignition wires. How old are they? And what brand?

I had that problem twice and both times it was the spark plug wires. The first time only two wires were replaced and the second time the dealer replaced the whole set. It was under warranty at that time. If your wires have never been replaced, that might be a good place to start.
Replacing the wires also cured my mother's Buick Century for the same symptoms.

[jph2424]

Thanks for the info. i replaced the TSP with no change. I'm going to replace the wires and plugs and see what happens. Stay tuned.

[jph2424]

I changed the plugs and wires. No more mis-fire. 190,000 miles and runs great. Thank all of you for your help.