Sometimes my truck won`t start. Starter turns over but motor won`t run, you can hear the fuel pump priming. If you wait ten or fifteen minutes it starts as if there was no problem and runs fine. It used to start as soon as you turned the key, but now I sometimes have to hold the key longer for it to start. I just changed the fuel filter, did not help. I have had this problem for several years & just worked with it. I had an auto-start installed after market before this problem started, dealership told me to have it disconnected but it did not help.

SOURCE: 2000 GMC Jimmy will not start

The oil presure switch does have some bearing on the problem but my suggestion is to change the coil. I had a the same problem with an astro van. I changed everything that you have described and it fixed the problem just for a little while and then all of a sudden did it again. I changed the coild and the cold start swithch and never had the problem again.

SOURCE: hard starting after sitting awhile

I posted the second problem, I did get my car fixed. the problem was a weak fuel pump

SOURCE: Cant get truck to stay running

did you try the fuel filter

SOURCE: 1995 safari van w stalls when giving it gas.

maybe your iac valve is not working? it takes place of a choke or temp sender to computer could be bad which controls t I.A.C. known as the idle control valve,do you have any codes?

SOURCE: Have a 98 gmc 5.7 truck have to prime to start truck.

Sounds to me like either your pressure regulator is bad or you have a loose fitting somewhere in the fuel line from the fuel pump to the engine. When you turn your key to the on position, you should hear the whine of the fuel pump until it builds pressure. When you shut the truck off the pressure regulator should retain the pressure for a certain amount of time but if it don't close then air is allowed into the fuel line and the fuel drains down to fuel line away from the engine. Next time you try and start the truck after it has sat for a while try turning the key on until you hear the fuel pump whine shut off, then repeat it 3-5 times and then try to start it. Basically that is running the pump enough to get the fuel back up to the injectors. Check for loose fittings in the fuel line, or cracks in the fuel line and if all that is fine then replace the regulator.

Hope that helps

Testimonial: "sounds like a good idea i will try that THANKS!!!"