The problem isn't so much the failure of the solenoid valve as much as hooking it up incorrectly or knocking the plug or the hoses off when working in that area. Very easy to check with a timing light. While checking the vacuum advance you should also (just because you are already hooked up) check the mechanical advance and the timing. Symptoms of a problem in the advance would be a noticeable lack of power, bad idle, low gas mileage, and knocking under load. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, billsfanmd@xxxx wrote: > I hear people talk about the spark advance solenoid located by the > distributor...Looks like alittle flying saucer :-) Is there a way to check to > see if it is bad? mine has the vaccum lines on it and the electrical plug but > just wondered the failure rate and symptoms? This does not seem to be a part > you would normally replace on a tune-up. > > Mike C > 2109 > > > [Non-text portions of this message have been removed]