Author Topic: Fast idle speed increases  (Read 2418 times)

Offline Joebrick

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Fast idle speed increases
« on: January 11, 2015, 07:08:35 AM »
I need advice on fast idle. 

My idle speed is set to 1300 RPM with cam on high step at cold start and that works fine.

Problem is that after the car warms for a few minutes of driving, the idle increases to 2200-2500 or so??

This speed remains until it gets hot enough to kick down and all is well after that.

I set the choke rod length correctly, nothing binding, what can I go after next to keep it from climbing like this?

73 Corvette 350 cu in Quadrajet.
« Last Edit: January 11, 2015, 07:13:59 AM by Joebrick »

Offline Cliff Ruggles

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Re: Fast idle speed increases
« Reply #1 on: January 17, 2015, 05:40:02 AM »
The engine rpm's should fall off as the engine warms up and fast idle cam falls to a lower step.  If rpm's are increasing, which is normal as the engine warms up, the choke is sticking, or staying on too long.

Is the choke coil heating up and opening up the choke flap?  Fast idle cam falling down accordingly?.....Cliff