Hey guys, I have a 2000 GMC 2500 4x4 with the 5.7l auto. When the truck is cold, it will start right up and run great. Once it gets warm, it doesnt want rev up in drive or reverse but will rev perfect in park or neutral. It idles perfect in park and drive. It also will interm die and is hard to start. Sometimes you have to let it sit for 20mins or so before it will start, then its hit or miss whether it will run in gear or not. Sometimes it runs fine other times it wont rev but idles fine in gear. I have a MT2500 Snap-on scanner. No codes are present. The fuel pressure at idle is around 55-60 psi. when you rev it, it drops a little but not much at all. Any ideas guys? Im stumped. Would a clogged cat cause this? It doesnt miss out, just bogs way down and wants to die when reved. The truck has 205k miles on it. Thanks for any and all help!
2000 2500 4x4 5.7l Hard to start when warm, wont rev in gear
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I think you may have an issue with the spider injector. Since the fuel pressure is supposed to rise when you rev the motor. Also take a close look at the cap and rotor (they crack causing issues) Also take a look at the throttle position sensor. there is a chance once the motor warms up and sends the heat that the expansion may cause the reostat (spelling) to expand enough that it wont make contact. And boy do i wish i had your scanner!!! those are sweet.
Ok started messing with it agian today. Now it wont start at all and it only builds about 45psi of fuel pressure. I took the fuel filter off and put my pressure test tee in-line where the fitler was, still only around 45 psi. Cranks over fine, has spark, im assuming it has crank signal since i can see rpm signal on the scan tool. Im going to try a new pump and see what that does since it wont build to 60psi. Is there any good way to daig the fuel injector spider going bad? Thanks for the help!
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