Everything!
Heater core.
Ignition control module.
Ignition sensor.
Ignition coils.
Oxygen sensor.
2 fuel injectors.
Fuel pump.
Front struts.
Front right wheel bearing.
Power window switches.
All of the above had to be replaced and since I don't have the expertise to work on cars it was NOT cheap! I quit fixing things and have since bought a different car. It is still sitting in my front yard because I feel it as brought nothing, but trouble and an empty wallet. I refuse to even think about repairing anything else on it!
When I first got this car is was great!
Great acceleration, left almost anyone sucking dust, handled well even in the snow. I think I may have got a LEMON, I saw it in an add in the paper and bought it from a guy who I didn't know. I think he just made it barely run and then sold it.
I feel sorry for you. I once bought a Mazda from a guy I didn't know and said he was a mechanic and looked after it well, but as it turned out the car was the worst lemon I have ever heard of and seen. No other car has had as much problems as I had so I finally was able to sell it. I love GM's and I'm sorry to hear about your mishaps with it.
Hey if you still have it sitting i'd be more than happy to take it off of your hands. the z24 is the one thing GM ever made right in the 80's. when mine met her early demise I was on the verge of throwing myself into traffic, and since haven't found one that was nearly in original condition.