Hello all, I have a 1988 Pontiac Trans Am GTA with a 305 TPI, all original with no modifications at all... Automatic transmission, 3.27 rear, all options except leather and the 350 TPI.

The problem is, when I give my car 1/2 to 3/4 of of the throttle, it shakes, like it doesn't have all the power... When I put the pedal to the floor, it shakes too, and become good after 1-3 seconds of flooring it... Sometimes when I keep it stomped for like 10 sec, it do it for 1-3 sec, became normal, beging to shake a again, normal.......

 

I need help... Please!

 

Could it be in the tranny?
Just a thought.
IF its definitely in the motor what about the cat being stopped up?

 

The tranny as been rebuild less than 15 000 miles ago... And it was shaking sometime when I was just stopped at a light. I don't have a cat anymore.

 

So I hope I find the problem fast, my car was supposed to be on a dyno tomorow the 24!

 

What about the MAF sensor? I remember my car sputtered at idle and low mph, but it was more like a bogging down feeling. Did you recently move the intake? Maybe it's disconnected.

 

I took the GTA out today again... The problem is still there but less than the other time.

When I'm at a stop light, sometimes it do a little shake here and there, is it a miss? When I remove the foot from the brake and push the gas pedal, it shakes while accelerating. When I put it to the floor, sometimes it go like normal, sometimes it shakes a little and accelerate not as fast, became normal again, slow, fast, slow.......

What do you guys think it could be beside a bad fuel filter?

 

I decided to change the fuel filter tomorow... I'm looking at ACDelco Canada's web site and it come up with a GF652 filter ans a GF481C. What is the difference between the 2? On the US site I get only the GF652...

Thanks!

 

Plugs, wires,Cap, Rotor all good?
Maybe a plug wire got into the manifolds (or headers).
Or the wires may be breaking down.

 

what kind of shake is it??? are the rpm's fluctuating when it shakes? or staying steady?? give us more info please!

 

It seem to stay pretty much steady... It doesn't go down, but when I floor it, it doesn't go up as fast as normal!

 

Another guess:
Harmonic balancer came apart?
That would cause a shake.
The rubber ring breaks down over time.
The outer ring slipps off. Usually makes some noise though.
Hard to guess not being there.

 

This happend to me 2 years ago. Disconnect your battery for 15 minutes then connect. Lemme know if it still runs like that