Just picked up a 1991 s10 Blazer with the 4.3 v6. When I start with a cold engine I get a VERY high idle speed. By cold I mean like the first start of the day or after its been sitting for a few hours. I live in Fla and it will do it with an outside temp in the 90's. Starts fine, drives fine and no computer codes. Any idea where I should look first?
Fast idle on cold start
Jun 11, 2004
2 Replies
This can often be stopped by goosing the throttle after you get it running. Doesn't solve your problem, but gets it to quit till you have the solution.
Big Chris
might need to put a scanner on it before you fire it up and see what the coolant temp sensor is really reading , might be 90 out side but temp sensor saying its 50
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