Author Topic: Carb keeps idling at 1250  (Read 3495 times)

Offline Bigmoe

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Carb keeps idling at 1250
« on: June 11, 2017, 05:29:26 PM »
Just rebuilt this carb rebushed the shaft, everything new. The best stuff cliff could sell me. On a Pontiac 461 e heads and manifold. Problem is, I set my idle 800-1000 rpm (warm motor) idles fine rev it up drops back to 800-1000. Take it out for a drive, pull in my drive way 1250 rpm every time. I crack the throttle to kill the choke but that doesn't help. Other than this the carb performs flawlessly

Offline omaha

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Re: Carb keeps idling at 1250
« Reply #1 on: June 12, 2017, 12:37:18 AM »
  Hard to say for sure but I will guess. Maybe some things to investigate. Carb linkage from gas pedal or choke linkage might be hanging up.  I personally had the problem with the pedal linkage and yes it was a cable linkage. It doesn't take much. Another culprit could be the distributor. I've  also had  sticky distributor weights  cause problems like you have. As far as carb issues, I cant see the connection unless it could be a slight misalignment  of the throttle plates but it would seem that would affect the situation at all times. However it could be something else to investigate. How big is the cam in your 461. [choke can malfunction also]. Good luck

Offline Cliff Ruggles

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Re: Carb keeps idling at 1250
« Reply #2 on: June 12, 2017, 03:27:05 AM »
Engine specs?

Carburetor number?

How much timing at idle?

Check to make sure the throttle plates are all fully closed and well sealed up.  Very common problem after bushing installation to not get the plates well "indexed" and have some unwanted air getting by them, or sticking a bit when they close and letting in enough air to have the engine idling too fast.

Timing is another big issue, weak distributor springs, installing one of those aftermarket kits into the distributor, running manifold vacuum to the advance and having too much timing at idle speed, etc......Cliff

Offline Bigmoe

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Re: Carb keeps idling at 1250
« Reply #3 on: June 28, 2017, 08:04:57 PM »
My problem was the electric choke, it would hold the fast idle cam on the last notch. Problem solved. What a great carb!!

Offline Frank400

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Re: Carb keeps idling at 1250
« Reply #4 on: June 29, 2017, 03:25:49 AM »
Good news !

Offline Ethan1

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Re: Carb keeps idling at 1250
« Reply #5 on: June 29, 2017, 05:48:42 AM »
Ethan

1972 Chevelle

(oo______oo)