High idle and booster question

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Oct 21, 2003
Be prepared for a long post.

Background: This vehicle has a new starter, alternator, fuel filter and complete tune up(plugs, wires, cap, rotor) with in the last two weeks.

It was around zero degrees F last night. This morning I start the 62 up and it starts great! however the high idle kicks in and it is no big deal right? Well the high idle starts to fluctuate a lot like it can't decide if it is warming up or not. the fluctuations started almost imediately with in 1 minute after startup. So I let it go, not knowing if this is normal, and it keeps doing this? Once it gets warm it idles down to the appropriate 600 rpms. Then When I drive it and put it in park the idles shoots up to 900-1500 depending on how it feels that day? So what gives with the fluctuating high idle? Is there a temp sensor that is going bad?
As far as the high idle goes after driving I assume my "TPS" needs a check and adjustment? However could a Leaky Brake booster cause a high idle situation? HOw do I tell if the booster is leaking? WHen I go to stop I stop fine but if I let up on the brake once then aply again I get more posotive feel. There are no leaks in the system so is my booster bad or do my rear brakes just need adjustment?
I think that makes a short story long so can anyboddy help me out? I am fairly mechanicaly sound where I have built engines bfore, but When it comes to modern vacuum and idle circuits I am just trying to catch up. Thanks for you help so far and look forward to a lot of responses.

-Seth in Wisconsin
A common problem on 60s, not sure about 62s, is the fitting that attaches the brake booster vacuum hose to the intake manifold becomes blocked. Its a steel thing with discs welded to it that look like a heat sink. It unscrews from the manifold. Clean it out with a wire or a small drill. This might help the power brake assist when pushing the pedal repeatedly. HTHs Can't help with the idle problem.
Can't think of the name of the thing (high idle solenoid?) kicks on when the a/c is turned on. I know you're NOT running the a/c but it could be this solenoid? going bad. Maybe Poser, Hammerhead will know.

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