Fast Idle...

[Capman2k]

Got my K5 from the shop finally on Thursday and so far so good... they put on a new fuel pump and a new line, both of which I put on a couple weeks ago

Anyway... For the last few days (well, since I got it) it's been idling really high.. I'll start it up and it'll go like normal but when I give it some gas, it goes pretty fast... When I'm driving it's normal most of the time, but a couple times on the way home from school I've really had to step on the brakes to stop it because it just wants to keep going... When I put it in park, it races again, and when I shut it off, I can feel the gas pedal push up against my foot like it was down just a little bit but not much...

I'm thinking it might be the throttle because my Subaru did the same thing once and we just adjusted the throttle cable, but I can't find it on the K5 (??) and no diagrams of it in the Chilton's book...

79 K5 Blazer Cheyenne.... That's all I have to say about that.

 

[4x4blazer]

Mine did that once and it was a stuck throttle valve. Had a lot of gunk on it. Just sprayed it down real good with carb cleaner and fixed her right up.
Could also be a timing or vacuum problem.

 

[dyeager535]

Likely choke adjustment. Warm the truck up, then when it starts fast idling again, with truck running, take off air cleaner lid and see if choke blade is full open or not, it should be when the vehicle is hot of course.

You can also try pushing the accelerator linkage on the carb FORWARD to see if idle goes down, if it looks like the choke blade is full open. Since its not constant, I'd doubt it was the idle speed setting on the carb.

No throttle cable adjustment. You can check for binding by removing the cable end at the carb, and testing for smooth operation.

Dorian
My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</a>
No anti-theft measures on your truck? No pity when its stolen

 

[TorkDSR]

to find the throttle cable just have someone pump the gas while not running, it should be on the drivers side of the carb, there is a stop screw that the throttle linkage lever thingy rests against, unscrew it a bit that should lower the idle, it's real simple

Tork DSR
I just got a winch, it takes the fun out of things.