Re: 56 Patrician

Posted by BH On 2008/1/6 21:00:34

One part that was commonly stocked on GM dealer shelves back in the 1980s - moreso than an ECM or even a fuel injector - was the coolant temperature sensor (used for the ECM, not the temp gauge).

Perhaps that was because one or two parts fit many models, regardless of the number of cylinder, but if that sensor puts out the wrong value, a wide variety of symptoms can occur ranging from the sublime to the ridiculous. Poor cold operation is usually a dead giveway, but that could also be due to a computer. Before you do anything else, however, inspect the wiring in the engine bay for rodent damage.

The coolant temperature sensor is probably the least expensive parts you can throw at those cars, but you really need a factory shop manual or equivalent to do a proper diagnosis on any electronically managed engine - EFI or carbureted.

Good luck!