Hi I’m new to this site and I have a 1989 Pontiac Firebird had it since middle school and sadly I wasn’t into cars at that time so the car pretty much just sat In the parking lot now that interest has peaked I’ve been trying to get it working which I managed to with the help of my dad but now I have a problem neither of us can fix the car turns on but vibrates like crazy and it won’t accelerate well has no horsepower basically running on just idle it’s a 2.8L v6 I’d appreciate the help I really love this car and it hasn’t gave up on me and I won’t give up on it

 

You might post in the tech engine forum.
check tuneup items and if it’s sat for a long time it’s probably due for injectors.

 

It will probably need a complete tune up....plugs, wires, oil change and all filters replaced. Drain the gas tank if you can or add as much new gas with seafoam green fuel treatment as possible. It might have a misfiring cylinder for the vibration if it is parked and running. I would change all the other fluids out after you get the engine running smoothly as well. Good luck!

 

I'd try a proper tune-up first. If that doesn't work, the harmonic damper could be bad...