Hi Everybody!
Need some help!
When I start my car it shakes hard on idle(800rpm). It's gone if It goes over 800.
Secondary. When I drive it and the tranny goes into overdrive it starts shaking again. If I'm crusing nothing, but as soon as I accelerate it gets bumpy-shaky like I have bad balance on my tires and I drive it at 80mph.
I know it's not the best diagnosis, but I hope somebody had same problems and can help me!
Thanks a lot!

 

There are several possibilities. You could have small vacuum leaks, an ignition system that is not at 100% efficiency, fuel mixture issues, including low pressure or failing injectors, compression issues from worn rings/valves, or mechanical damage problems like a worn cam lobe, damaged piston or valve train, etc.

The easiest thing to check is the ignition system. Even though it could be any of the other listed causes, diagnosing all of them requires that you have an ignition system that is reliable, so you might as well go over that first.

Remove and inspect the spark plugs. Test the ingition wires. Inspect the distributor cap and rotor. Test the ignition coil. Go from there.

You should also scan for stored error codes, make sure the TPS voltage is set correctly, and set the base timing.

 

Thanks a lot!
I'll check the ignition first!