Monte Carlo Ignition Module Problemsby Lee Sallings
The Chevy Monte Carlo has changed from the the V-8 equipped rear-wheel-drive platform of the 1970s and 1980s to the V-6 equipped front-wheel-drive platform of the modern version. But the ignition module is still the heart beat of the electronic ignition. Common problems with this system, as with most General Motors ignitions, are related to the module not triggering the ignition coil or not having timing control.
The ignition module's function is to turn the power to the ignition coil off and on. This causes induced voltage into the secondary of the coil and a spark to be released to the spark plugs. Modern ignition modules have electronic circuits that control timing as well as spark. One common symptom of a bad ignition module in the late model distributor-less ignitions is a lack of timing advance that may cause hard starts and loss of power. This can be checked for with a timing light. There should be advance and retard of timing when the engine is revved.
Many times the first sign of trouble with the ignition module will be a hot stall while driving. This problem may show up as an engine stall when the vehicle is hot. After cooling for a few minutes, the car will start up and drive again until the module gets hot again. The easiest check is to see if the coil(s) is firing. Disconnect the coil wire from the distributor and hold it close to the engine block. Then, while a partner cranks the engine, see if a spark occurs. If no spark occurs, you may have a bad ignition module and can verify it in the next test. If a spark does occur, start the engine and run it until it shuts off from heat. Then test again. If you still have a spark, the problem is not in the module. Another option is to check if a signal is coming from the pickup coil in the distributor. This is the coil-like device inside the distributor. While a partner is cranking the engine, see if you have a voltage output with a volt meter at the wire connecting the pickup coil to the ignition module. If so, replace the module.
Replacement is straightforward: located under the distributor cap or under the ignition coils in the distributor-less systems, it is a simple bolt-on part. The quality of the replacement part can affect the performance and life of the repair. High-quality parts have more robust components and last longer than the cheaper parts. In some cases the cheap replacement part may not work at all and lead to a wild goose chase for another cause. Name brands like A/C Delco are the way to go here.