Power Valve, can it make a hesitation?
 

If your power valve is blown out or not working can it cause your engine to hesitate or bog during acceleration?? Or the power piston that pushes on the valve be worn out and cause that?? This is on a Rochester 2BBL. Because I have had a lot of good backfires and I hear that that can cause your power valve to blowout.

Re: Power Valve, can it make a hesitation?
 

yep

Re: Power Valve, can it make a hesitation?
 

So you are saying that I need to replace my power valve or power piston or both???

Re: Power Valve, can it make a hesitation?
 

Typically a power valve enrichens the fuel mixture to compensate for the sudden drop in vacuum and signal when the hammer is dropped, so yes it can cause a stumble when accelerating

Re: Power Valve, can it make a hesitation?
 

So power valve or both power piston and power valve?????

Re: Power Valve, can it make a hesitation?
 

No rubber parts to blow out on those 2bbl power valves, unlike a holley, the 2bbl is all metal and brass.

Re: Power Valve, can it make a hesitation?
 

So Green Machine, what are you saying that the power valve cannot get blown out??? But can it wear out.

The BIG QUESTION. Should I replace the power valve or power piston or both????

Re: Power Valve, can it make a hesitation?
 

Anything can wear out, but can you find parts for those ? The needle type valve at the bottom is easly replaced, doubt if it is worn out though. The piston in the carb top most likey would wear into the carb body, new one may not help. Check accel pump shaft play in carb top, and make sure the light aluminum ball is installed under the spring and t-bar retainer for the accelerator check valve. There is a larger steel ball in the kit that will fit in there and give you a weak pump shot. Adjust float level so it is level with the carb top. Higher fuel level in the bowl will help fuel to flow from the boosters sooner as you transition from off idle.

I still think those carbs are best replaced with almost anything else.

Re: Power Valve, can it make a hesitation?
 

Tom is right EXCEPT for that last sentence. but then again only a 4MV can trump a 2GC.

Re: Power Valve, can it make a hesitation?
 

Well I'm eventually going to replace it. Right now I just want to get it to run well enough to take out on the road and drive it around a little bit. I'll check into that stuff you mentioned Green Machine. Thanks:)