high idle

[the_legend_1981]

When i come to stops my truck idles real high. Sometimes I can get the idle to kick down, but other times i can't. Then when i go to shut it off it will diesel if its idling high. I turned the idle down...not sure if it could be the throttle cable, choke or what. Thanks for any input.

[the_legend_1981]

its the actual throttle on the carb thats sticking i just went and checked it. i could set it back in place with my hand. how can i go about fixing that?

[oldwhity]

Mine used to do that all the time. I sprayed the linkages down with some carb cleaner and it stopped. I would try that before trying to readjust any linkages.

[the_legend_1981]

Would it be better to use lubricant?

[78 Chevyrado]

no , only use carb cleaner, it will lube it and using oil will catch a lot of dirt being out in the open and gum it up sooner.  spray carb cleaner in it while working the linkage and it will do the job.  if you have cruise control, make sure it's not binding, I had one cause that same problem one time.

[Stewart G Griffin]

The other thing i want you to check is the throttle spring itself.  Can you post a picture?  What may have happened is that the spring has lost tension and overstretched.  This happened to me last yr. and i was getting the same symptoms.

[the_legend_1981]

I did sll that stuff even changed the throttle spring...then I finally figured it out as I was doing that. The carb was just a little bit loose, I tightened it and it hasnt stuck so far.

[Lt.Del]

now that would make for quite a vacuum leak, which is basically what it is and kept the idle high.  Too much air.

[the_legend_1981]

yeah it was the last thing i expected it to be.

[Stewart G Griffin]

OK, cool.

[VileZambonie]

Is this a quadrajet? If so you're probably not kicking off of the fast idle cam all the way. Check the choke break.