GM Truck Club Forum banner

2000 2500 4x4 5.7l Hard to start when warm, wont rev in gear

2687 Views 3 Replies 2 Participants Last post by  murdog94
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!
1 - 2 of 4 Posts
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.
Well I forgot to add Fuel Pressure Regulator on the Spider Assembly more than anything. But the low Fuel Pressure is indicative of a bad pump. If you dont have 58 PSI your engine wont start. So time for a new pump.
1 - 2 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.