I own a 1987 Buick LeSabre with the 3.8L FI engine that has 90,000 miles on it. All of a sudden the engine will not start and it showed no previous signs of a problem. After a limited amount of troubleshooting, I noticed that two of the three coil packs were carbon tracking (arching) from the coils to the underneath ignition module. Based on this, I replaced the ignition module, all three coil packs, spark plug wires and spark plugs but the engine still doesn’t start.
Recently, I replaced the engine control module and the camshaft position sensor but it didn’t solve the problem. Fuel pressure checks out OK with 35 psi at the fuel rail, injector pulse checks out OK based on a noid light test at all six injectors. The spark plugs are also wet with fuel when removed. I also performed a spark plug test via an inductive test light and also removed each plug and grounded it to the engine block to check for spark. Both test results were OK. The newly-installed ignition module was also recently removed and tested to verify correct operation.
A compression test on each cylinder was then performed. Each of the cylinders registered approximately 150 psi after three revolutions. Bottom line: fuel delivery and ignition appear to be fine. Based on the troubleshooting charts found in the GM Buick LeSabre authentic technicians manual, the ignition module and engine control module appear to be operating correctly.
No diagnostic codes are present on the OBD-I computer besides Code 12 which indicates the computer is working correctly.
Any ideas on what to check next? Any help would be greatly appreciated.