Engine revving
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MSEE
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From: Austin, TX
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Fleet Mechanic
Joined: Mar 2004
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From: Hesperia, CA
My 77 is doing the same thing. The rpm’s are up when pulling up to a stop sign. It is a major bitch to get that thing stopped with that 460 pulling while you are trying to stop. I have discovered that I can put my toe under the pedal and lift up and it will go back to idle. That tells me that it is in the throttle mechanism, but I have checked out the throttle rod from the pedal to the carb and it is free and not binding on anything and I am clueless as to what is causing it. You might try to pull up on the pedal with your foot and see if you are having the same problem. That would give you an idea as to where to look. I will let you know if I figure out what is causing my problem.
New User
Joined: Oct 2007
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I had similar problem, more like wb6vvv describes, and it was the throttle return spring. It had stretched out over time and was not helping throttle return all the way back and letting engine stay "revved-up" a bit. Replaced spring, problem went away immediately.
Postmaster
Joined: Oct 2008
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From: Renton, WA
Yes could be a throttle return spring problem.
But because you seem to say it happens when you hit the brakes it could be a brake vacuum assist going bad. They shouldn't actually allow much air into the motor via the vacuum line but if they devolep an internal leak they can.
Pay attention to see if it's all about the brake pressure.
But because you seem to say it happens when you hit the brakes it could be a brake vacuum assist going bad. They shouldn't actually allow much air into the motor via the vacuum line but if they devolep an internal leak they can.
Pay attention to see if it's all about the brake pressure.