Old Buick won't start when warm; starts fine when cold

parkingbrakes
buick

#1

My '94 Buick Park Avenue often doesn’t start when the engine is warm. It starts fine when cold. The battery is not the problem. It tries…but the car won’t start.


#2

If I were a betting man, I’d say this sounds a lot like the ignition module, which was the cause of chronic heat-related problems on GM products of this vintage. If possible, you should try to put a spark tester on it next time it won’t start (this is a little gizmo you put in between one of the plugs and wires that blinks if it’s getting high voltage-- they’re about $2-3 at an auto parts store)-- this should narrow the problem down to fuel or spark.

I’m also assuming “it tries…” means that the engine cranks fine, but won’t catch?


#3

Thank you, Jack.

I’ll give that a try.

Yes…the engine cranks fine, but won’t quite catch.

Stan


#4

You can use a spark check which doesn’t require disconnecting anything. There are pencil size spark testers which attach to the spark plug wires. The spark tester will flash about every two seconds during cranking. This would indicate that there is spark. A drawback might be that the lamp is rather dim. So, you would need to shade the spark tester and be rather close to it. You might have to go on line to fine this type of spark tester (ebay, amazon.com, etc.).


#5

Thanks, again.

Stan