I'm back. Different vehicle, different problem.

2002 Silhouette runs great. Wife drives it about 5 miles, shuts it off for about an hour and then it will turn over but not fire up. I'm not there when it happens, but when I arrive it starts right up. Did the same thing about a month ago. Acts like it is out of gas. Never does this on first start in the morning. I relalize its vague, but thats all I have right now. Trying to head off having the wife stranded to far from home.

Check the security light and observe what it is doing when this happens. Could be a VATS issue.

is it a 3400? sounds like crank pos sensor or ign module. maybe you can take it yourself do the same thing and see if it has spark or not when it wont start.

Yes, it'* a 3400.

both of those things are tight to the block and can be effected by heat and will make you loose spark when they go bad. if you have a heat gun you can carefully warm them and if the engine cuts out you know you have your problem

Justin is probably on the right track with the CPS, but I still would like to know if the security light is doing anything when the car won't start. Has the car stalled while driving? Is this getting progressively worse with time?

Several weeks later the van would not start again. No warning lights. I was able to check for spark and it was fine. I just recently changed the fuel filter so I can rule that out. New battery. Fuel pump is operating. Moments after I arrived, which was about 20 minutes after she tried to start the van, it fired up. Any more Ideas?

By the way, it has never stalled while running, and no it is not getting progressivly worse. In fact, it has been one month since it last happened.

I had something similar happen with my GP; the first time it acted up at a car show, but it started up on the third try. The second time was months later in my garage at home, but this time the gremlin stayed long enough for me to troubleshoot.

The culprit turned out to be a faulty fuel pump relay. The relay would click and the pump would prime with the key on, but then it would crank and not start, because there was no fuel pressure at the rail. Swapped it for the spare I kept in the glove box, and it fired right up.

How do I test the fuel pump relay?