2000 GMC Bad Idle And Hard To Start

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Daniel

2000 GMC Bad Idle And Hard To Start

Unread post by Daniel » Wed Nov 07, 2012 1:34 pm

2000 GMC K2500 5.7L. My truck will only start if i push the throttle pedal and then it idles poor and when i drive it every time i go to stop it shuts down. What else could it be? I replaced idle air control valve, cleaned throttle body.

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ProTech
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Re: 2000 GMC

Unread post by ProTech » Thu Nov 08, 2012 8:03 pm

You could have a problem with the injector spider and/or fuel pressure regulator. These are both located underneath the upper intake (plenum), so you'd have to remove it to take a look. Usually on the 5.7 engines, either the fuel pressure regulator ruptures and leaks gas into the intake, causing hard starting and stalling out as you slow down...OR...one or more injectors can be stuck open or closed (probably open) and messing things up that way. The fuel lines inside the plenum can also leak and cause the same problem. You didn't mention it, but if you happen to have a check engine light on as well with the problem, a quick scan for codes can usually lead you in the right direction. If there is no check engine light, start off with the basics...check fuel pressure and see if it drops off, check for a clogged fuel filter, any possible ignition problems, vacuum leaks, etc. If all that checks ok, I would recommend pulling the upper intake off and checking inside there.
GM Dealer Technician For 18+ Years
In the automotive industry for 20+

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