1999 chevy silverado 5.3 vortec Idles too high

rrtgal
Posts: 1
Joined: Mon Dec 17, 2012 1:13 pm

1999 chevy silverado 5.3 vortec Idles too high

Unread post by rrtgal » Mon Dec 17, 2012 1:20 pm

my sons truck,when he starts it up idles up so high its scary! it continues to idle way up then down till he takes off and when he does take off it leaves a huge rut in the yard from it. also when its running and he stops at a light or stop sign it continues to wanna kinda jump forward, he has to be really careful. we replaced the mass air flow sensor on it but it did no good. please help!

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ProTech
Posts: 651
Joined: Wed Oct 17, 2012 10:08 am

Re: 1999 chevy silverado 5.3 vortec

Unread post by ProTech » Tue Dec 18, 2012 8:06 pm

Check for any vacuum leaks that area causing the idle to be so high. The intake gaskets are commonly known to go bad and let the intake 'suck air' causing vacuum leaks and driveability problems.

Otherwise, check the throttle body for any carbon build-up that might be holding it open a bit. And check the linkage/cable for proper routing and attachment. Another thing to try would be to check the computer for any stored codes by getting it scanned.
GM Dealer Technician For 18+ Years
In the automotive industry for 20+

Blacklion
Posts: 1
Joined: Thu Jan 01, 2015 5:00 am

Re: 1999 chevy silverado 5.3 vortec Idles too high

Unread post by Blacklion » Thu Jan 01, 2015 5:08 am

Check for any vacuum leaks that area causing the idle to be so high. The intake gaskets are commonly known to go bad and let the intake 'suck air' causing vacuum leaks and driveability problems.

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