What is the average RPM of your idle?

General Discussions Forum
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Hello everyone! My 1990 Chevy 1500 with the 5.7 engine is mine. It has just come to my attention that the vehicle idles around 2,000 rpm for a short while before gradually hovering around 1,500 rpm. I’m just curious if this could be a vacuum leak or if my concern about things going wrong is excessive.

Could the truck’s changes be the cause of the 1,500–2,000 idle rpm? (Big cam, long tube headers)

In addition, the AC seems to be having a surge problem when I switch it on. Could this be related to the fan belt or something else?

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You seem to be having an issue. In general, those older machines that were even altered shouldn’t idle above 8/900. They would be down to about 600–700 warm stock.

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Older Chevys may be different, but in general, I know it shouldn’t be idling at 1500. At 550, my 2001 5.3 idles.

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Idle RPM is a measurement for physical engines.

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