I have a 93 bonneville that turns over but won't run. I've replaced the ICM,ECM, crank sensor,and the cam sensor. I checked for spark on cyls 1,3,5 and there is no spark. Then I took off the coil packs and checked the ICM prongs. With ignition on lower prongs will light up a 12V light. Upper prongs don't show anything. For about a week, it would sometimes not start on first crank, but it would always start on second or third try. I backed it into the garage and the next morning it wouldn't run. It was running well before this. My next step, because my wallet is crying, is to go over every ground I can find. Am I looking in the right places?

In case anyone comes into this situation, I went over all of the grounds and cleaned them. The connection points under the coil packs and ICM weren't corroded, but they had a slight silver sheen. I brass brushed them and put them back on. It works great now! The idle is smooth and all guages are showing good.

Glad you found the problem. Sometimes it'* a simple fix.

I have a 1993 SSEI Bonneville does anyone have a step by step on how to replace the fuel pump on this car