jeffx50

Hello all; I'm new to this forum, but I'm in real need of some experienced mech wisdom.
I went out to my 1992 Silverado 2500 (with 350 CID) this morning and when I fired it up it automatically started idling at about 1700 RPMs instead of the normal 650. Even though I shut it down to check it out it restarted in the same way. In gear it is running at about 1200 RPMs.
A mechanic for our company thought it might be an air leak around the throttle body base, but this is outside my field.
Anyone familiar with this problem?
Thanks in advance!

country_09

Vacuum leak somewhere from the sounds of it. You can get it fogged and find exactly where the leak is. I believe the dealer does it

therewolf

Hi jeffx50,

Welcome to the Chevrolet Forums.

I'd start by running OBD trouble codes. Some times when a

code is tripped, the on-board system tries to compensate.

in2pro

If it is a vacuum leak you may be able to narrow it down with a can of starter fluid, spray around the engine in various areas and listen for a change in the engine...
But a preliminary check of vacuum hoses is a good place to start...make sure they all fit snug, are not cracked or split...

Being its a 90's model you have a throttle cable, so make sure it moves freely and is not hung up... if it is the cable avoid using lubricant as it may free it up for a short while but the oils will collect even more crud and gum it up good...