My 87 TBI 350 idles high because the main housing gets worn out where the main butterfly shaft runs through it so it hangs up and keeps the throttle cracked open a bit causing the high idle. If I quickly pop my foot on the pedal and let it pop up it will idle down to normal. I have been told you can have it worked over for a couple of hundred clams but I may just go with a aftermarket TBI instead.
A forum community dedicated to all General Motors truck owners and enthusiasts. Come join the discussion about performance, lift kits, wheels, tires, modifications, troubleshooting, maintenance, and more!