High idle?

1978 DODGE TRUCK
20 MILES • 5.9L • V8 • 2WD • AUTOMATIC
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BLAKE NORMAN
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Fresh la 360 build, with high flow heads, mild cam, can't get idle down below 1,500 after warm and choke open, used smoke machine, no leaks, all new ignition parts, fuel pressure regulator at 6 PSI, new Holley 750 and new Edelbrock 650 both high idle, when i put my hand on top of carb to limit air it smooths out and drops idle down sounds great.
Apr 22, 2024 at 4:11 PM
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STRAILER
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You could have an intake manifold leak (lower inside the engine), when it is running at high idle remove the oil filler cap with the PCV valve removed to see if any vacuum is present. Also, block off the power brake booster vacuum line. Does the engine have an EGR valve? Can you upload a picture of the engine so I can see it?

This guide may help:

https://www.2carpros.com/articles/stall-at-idle

Please go over this guide and get back to us.
Apr 23, 2024 at 10:31 AM