Its kinda hard to give a good diagnosis over the internet, but i will try my best. Just figured maybe someone will maybe know what im talking about. Ok this started about 2 days ago. When ever i have it in drive or sometimes third, and i am just crusing at low rpm's and give it a little to gas to go a little faster the car starts to shake and vibrate up in the front. But when i get on the gas real hard it downshifts and the car pulls real hard and the tires still break lose. Also it idels fine and its no missing or anything. It just does it when the car is underload thats it, the noise sounds like its the motor but i don't think it is, cause it still idels and pulls fine. i tink it might be tryin to find overdrive to soon. I have changed the fuel filter and thats it. Also the car is a 94 trans am. Any ideas would be helpful thanks!

 

Check your plugs for sure. You might have put in a tank of bad gas. Did you fill up recently? Try some lucas injector cleaner and some new plugs.

 

Yea thats what my dad was saying.... Yea i have filled up twice since, once from luke oil and the other at wawa. Both times i put in 93. He was sayin either bad gas, fuel injectors cloged, water in the line from a really cold night, or a plug. But we kept messin wit it and it idels fine and still pulls hard with what seems to be all 8 cylinders firing. Could a bad plug or clogged fuel injector still do this? I will get some of that stuff tommrow at pep boys and try it. Thanks for ur help.

 

Yup it can still do it. Might also be an optispark but let's start simple.

 

my pronlem im having is almost the same i replaced the plugs and didnt fix problem...i have a new fuel filter and i dunno where to go from there

 

In this order, plugs, wires then optispark. I had that same problem and I did all of them and it fixed it.

 

Yea ill try plugs and wires...I am almost positive its not the opti since the car has only 84,000 miles on it. But thanks for the help...