Questions and Answers

Oldsmobile Cutlass Dies Hot Q. Vincent, My 1991 Oldsmobile Cutlass Supreme has a stalling problem. The engine is the 3.4 liter dual-twin cam unit. The transmission is an automatic and the mileage is 179,000 (the engine was replaced at 170,800 miles with a new 3.4 liter engine, as was the original).

The replacement was a complete engine using my original peripherals. No ABS. Equipped with P/S, A/C, cruise control and rack and pinion steering. The problem manifests itself at idle or at low speed with little or no acceleration (no throttle), usually in heavy slow moving traffic. The engine immediately restarts.

The original engine experienced the same problem (at 100,000+ miles) and the dealer could never cure it. The engine was running cool so we replaced the thermostat. The timing belt was replaced (it was due) and the problem persisted. Eventually the Direct Ignition Module failed and after it's replacement the problem abated.

The original engine, some months later, had a valve failure and we decided to replace it. After a few months with the new engine, the problem returned. There are no stored errors and the service manager indicates that a copilot cannot be used to monitor the failure since the vehicle is too old. He thought that the Crank Sensor may be the culprit but the normal failure would be that the sensor would overheat and shut the ignition down. It would then be necessary to let the sensor cool before it would function.

As I indicated, the engine starts immediately and usually will not fail for some time unless I'm in heavy, slow moving, stop and go traffic. Recently, the engine has shut down a few times when I left it idling and exited the vehicle. I'm thinking about changing the Idle Air Control valve out of desperation. With the cost of replacement parts, shot gunning isn't very cost effective. Any help would be greatly appreciated.

Thanks for being there!
Tom

A. IAC valve would be on my list. Also would suspect the ECM of this as well. After it does this pull to the side of road and pop the hood. On passenger side in front of the wheel well is where the ECM should be mounted. Restart the car and try banging on the ECM and see if it makes the engine change RPM's. If so, this would be my prime suspect! Being under the hood and only when it gets hot. The ECM hates to get too hot.