sticking throttle body

Hi all,

I have a 2000 GMC Safari with a 4.3 Votec engine out of warranty. The throttle sticks when at idle but operates smoothly when above idle. It gets worse as the engine heats up. I don't think it is the cable. I think it is in the throttle body bore. I have read of this being a problem on Chevy trucks. Some have the said the solution is to have the throttle body and bore cleaned. Others have said GM recommends replacing the throttle body which I expect will be expensive. And ideas out there? I would prefer to avoid spending the bucks required to get the dealer to replace the throttle body.

Thanks,

Marty

Reply to
Marty
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Marty, this is a common problem that is well known by GM. The butterfly is lodged against the wall of the TBI's bore. Your idle stop set screw may be worn or improperly adjusted from the factory. This screw in normally hidden with epoxy or a metal disk inserted in the hole to hide it. You can find the screw by determining where the throttle cable lever stops. You can drill or scrape this obstruction away to gain access. Once you have access to the screw you will need a #15 Torx driver to turn the screw clockwise 1/2 to 3/4 of a turn. Once completed you will need to pull the ECM fuses to clear all learned setting the ECM has retained from the old adjustment. If you don't clear the ECM the idle will be slightly higher than desired. Good luck.

Rita

Reply to
Rita_A_Berkowitz

================================= Seams a little new to have worn out throttle plate/rod bushings. I would look it over real good again.

Reply to
Scott M

It is possible that it is just dirty/funky. Easy repair. Remove air horn and hold throttle open. Are there black deposits on the bore and/or throttle plate? If there are, get a spray can of carb cleaner and an old toothbrush. Do not use any metal brushes as it may scratch the soft aluminum bore. Hold throttle open and spray bore and plates with cleaner. Brush with toothbrush. Repeat. Final spray. Does not have to be immaculate, just reasonably clean. Reassemble air horn. Return wife's toothbrush to holder in bathroom.

If that doesn't do it you may have to dig deeper into it. This repair will take about 10 minutes and cost about $2, so it is worth a shot.

I check my Eldo and the wife's Camry every Spring when I do the regular maintenance and clean as needed.

HTH DFB

Reply to
D F Bonnett

You could also try a can of throttle body spray cleaner. Spray it where the butterfly valve pivots in the throttle body and work the throttle linkage as you are doing this. This cleans out the carbon or varnish or other gunk. This worked for me, but I have to re-spray it every year or so, or the throttle starts sticking again. SF

Reply to
sf/gf

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