Accelerator Pump

[Robert K.]

Looking to see if this is normal. I just had my Quadrajet rebuilt for my 1969 L-46. After reinstalling, the car runs great, and everything seems to be in good order. However, I had an intetresting thing occur when I put back on my air cleaner. The air cleaner base only fits on one way, as we know, but it does have a very small bit of "play" in the way it sits. I noticed, quite by accident, that if I rotate the base counter-clockwise a small amount (withing the amount of play that exists) the base presses doen on the accelerator pump on the carb. Not a lot, but enough to increase the idle some. The gasket is in place, so that doesn't appear to be the cause unless I need a thicker gasket.

Not a big deal at all, just wondered if anyone else has experienced this.

Bob

[Timothy B.]

Re: Accelerator Pump

Robert,
Are you certain the base has never been changed?
Simple things first.

[Martin N.]

Re: Accelerator Pump

BOB-
If you'd double up on the carb air horn to air cleaner base gasket, does it make a differance? Just asking.

Marty

[Clem Z.]

Re: Accelerator Pump

a lot of Q jet carbs used a thick carb to air cleaner gasket from the factory and this could be your problem

[Robert K.]

Re: Accelerator Pump

Thanks for the responses. Tim, I can't be certain that the base is original, but I have no reason to think it isn't. Everything else regarding the engine is original equiptment (block, carb, etc.) and the base fits perfectly except for the small amount of play. Marty, I believe that doubling up the gasket would probably eliminate it, and from Clem's post it looks like the original gasket was on the thicker side (I suspect for this very reason). The gasket I have would not be considered thick, so I may have the wrong one.

I am going to double it up for now and see if that works until I can get ahold of a correct gasket.

Once again, thanks for the replies, and have a nice weekend.

Bob

[Joe L.]

Re: Accelerator Pump

Thanks for the responses. Tim, I can't be certain that the base is original, but I have no reason to think it isn't. Everything else regarding the engine is original equiptment (block, carb, etc.) and the base fits perfectly except for the small amount of play. Marty, I believe that doubling up the gasket would probably eliminate it, and from Clem's post it looks like the original gasket was on the thicker side (I suspect for this very reason). The gasket I have would not be considered thick, so I may have the wrong one.

I am going to double it up for now and see if that works until I can get ahold of a correct gasket.

Once again, thanks for the replies, and have a nice weekend.

Bob

Bob-----


The original gasket, GM #3919812, was about 1/8"-3/16" thick. It was a BROWN fiber material.

The current GM replacement, GM #25511809, is a very thin, "grayish" fiber gasket. As I recall, I don't think it more than about 3/64" thick. I would guess that most of the Corvette vendors carry the GM replacement. Not Dr. Rebuild, though, he reproduces the original thickness gasket.

[Robert K.]

Re: Accelerator Pump

Thanks Joe,

As usual, you are spot on. I have exactly the GM replacement you described, right down to the color. Measured the thickness, too, and you are correct. No question that the original gasket thickness will alleviate the problem.

I will check out Doc Rebuild for the new gasket (I need some other stuff from him, too). Thanks so much for looking into it for me.

With regard to the good Doctor, it appears from the posts that most of the goods he sells is good quality, and fairly correct. Would that be accurate in your estimation? I need to purchase new vacuum lines and a new heater hose for my restoration.

Thanks again!

Bob

[Joe L.]

Re: Accelerator Pump

Thanks Joe,

As usual, you are spot on. I have exactly the GM replacement you described, right down to the color. Measured the thickness, too, and you are correct. No question that the original gasket thickness will alleviate the problem.

I will check out Doc Rebuild for the new gasket (I need some other stuff from him, too). Thanks so much for looking into it for me.

With regard to the good Doctor, it appears from the posts that most of the goods he sells is good quality, and fairly correct. Would that be accurate in your estimation? I need to purchase new vacuum lines and a new heater hose for my restoration.

Thanks again!

Bob

Bob-----


Yes, I consider Dr. Rebuild an excellent source for reproduction parts. In virtually every case, their parts are as correct as anything out there. In many cases, their parts are more correct than anything else out there.

[Robert K.]

Re: Accelerator Pump

Thanks Joe. Good to know!

Bob