93 GMC Jimmy Having Trouble Starting; Idling Rough?

[omigawdbananas]

I just bought a 1994 GMC Jimmy with around 157,000 miles. The Jimmy has new spark plugs and a tune up, and I just put in a fresh quart of oil.

Sometimes after sitting a little while, the engine has a little trouble starting. Once it starts it runs fine, but idles a little rough.

Any ideas on what might be causing this?

 

[Molson02536]

I just bought a 1994 GMC Jimmy with around 157,000 miles. The Jimmy has new spark plugs and a tune up, and I just put in a fresh quart of oil.

Sometimes after sitting a little while, the engine has a little trouble starting. Once it starts it runs fine, but idles a little rough.

Any ideas on what might be causing this?

Good chance that your EGR valve is dirty with carbon build up and stuck. Start with the simple and clean your throttle body and remove your EGR valve to clean. If it's to dirty to clean your EGR valve, replace it and make sure you use a new gasket for your EGR valve when you reinstall it.

If that does not help, there is a good chance that your fuel pressure regulator is leaking gas into your upper intake platinum or your fuel injector to your CPFI system is gummed up with carbon.

As mentioned, start with the simple and clean your throttle body and EGR valve. You may also want to try giving it the Seafoam treatment. Here is a link that should explain that.

Good luck and please keep us all posted. http://gmcowners.com/gmc-forum/showthread.php?t=13770