If the car starts and runs with the AMM disconnected but not with it connected, the AMM is likely shot. (Don't plug or unplug the AMM with the engine running) At least that was the symptom on my '88 when its AMM quit. It just wouldn't run after sitting for a weekend. Fortunately I could swap in the AMM from my '86 and then the car ran fine. I bought a new Bosch AMM rather than a rebuilt since I've read so many negative comments on rebuilt AMM's. Actually, I don't think there is much repair possible to the AMM except maybe for the platinum wires since th electronics is potted. I got my AMM on the internet, might have been The Parts Bin but I forget now. Anyway the car runs fine now.