Hey folks. I have come to understand that Buick LeSabres are known for their issues with their ignition modules but I’m trying to figure out the root to the problem. I have an '04 LeSabre ‘Custom’. I have had all of the coils and wires replaced and the ignition module. I had to replace some of the coils and ignition module twice since. I can already feel it going again. Thoughts?
hmm … that’s a tough one. The coils and ignition module are definitely heat sensitive, so they need to be installed with the proper heat sinking method, as it came from the factory. No mickey-mouse installing techniques using duct tape on those parts. Other ideas? If the system voltage was too high, due to a faulty voltage regulator maybe, that could cause an overheating condition in the ignition system, so have the battery and charging system tested. One some ignition systems they use a hotter spark when the engine is cold than when it is warmed up, so maybe something’s wrong with all that, and the hotter spark is being used all the time. The only other possibility I can think of is that the replacement units are aftermarket rather than oem.
Bad plug wires are often the cause for coil and module failures on that ignition system.
What about the spark plugs? Aged, high miles plugs can kill wires and coils. It’s also a good idea to use electrolytic grease on the plug boots and coil terminals to repel moisture which can also do them in.
I second or third worn plugs.
Good idea about the plugs. Especially true if the gap has widened due to miles beyond spec.
Make sure the alternator output voltage is within specs and also make sure that there isn’t excessive AC ripple voltage being generated.