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Old 06-21-2002, 08:18 AM
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Join Date: Apr 2002
Location: Southern, CA
Cobra Make, Engine: Everett-Morrison, FE 428
Posts: 164
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I agree with kountzcobra, the power valve should not prevent starting. The function of the power valve is to eliminate fuel starvation when you jump on the throttle. During cruise, the engine is producing good vacuum. When you accelerate hard, vacuum drops to almost nothing, thereby momentarily stopping or reducing the fuel flow. The power valve senses this drop in vacuum and opens up to allow fuel to flow momentarily until the vacuum increases enough to get the fuel flowing again. Basically it "fills the gap".

You may already know this but for others that don't, the proper power valve selection should based on approximately half of the manifold vacuum at idle. This would allow the valve to stay closed under normal acceleration and only open during heavier acceleration or loads.

The exception to this rule (like in my case) is if you have a radical cam that produces very little vacuum at idle. In this case, you need to monitor the vacuum during varying different driving conditions and base your power valve selection accordingly. Keeping in mind of course that the selection must still be capable of remaining closed at idle to prevent an overly rich condition.

I'm not an expert about this by any means but that's my understanding of how it all works. I think I would be looking elsewhere for the problem.

Good Luck,

Gene
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