LT-1 Holley Carb Problem Help

[Bryan M.]

What I thought was a fuel pump problem turned out to be a problem with my carb.
A little background info: The car had been running great without any issues until one morning when I tried to start it up. The motor would just spin over.
Whatever caused the non-start happened while the car was sitting in the garage.

Today, I got a chance to take a closer look at it and found that for some reason the accelerator pump lever was in a bind. I took the carb off and the bowls were full of gas so I knew the fuel pump was working. I fiddled with the lever and got it moving again so I put the carb back on and tried starting the car again. It cranked, but now has an off idle stumble. The carb nozzles drip fuel when pumping the accelerator lever. The car would start back up and idle continously while hot. The car would not start after I let the car sit for a few ours to cool down. The accelerator pump lever was once again in a bind.

What could be causing the accelerator pump lever to bind up?

[Clem Z.]

Re: LT-1 Holley Carb Problem Help

What I thought was a fuel pump problem turned out to be a problem with my carb.
A little background info: The car had been running great without any issues until one morning when I tried to start it up. The motor would just spin over.
Whatever caused the non-start happened while the car was sitting in the garage.

Today, I got a chance to take a closer look at it and found that for some reason the accelerator pump lever was in a bind. I took the carb off and the bowls were full of gas so I knew the fuel pump was working. I fiddled with the lever and got it moving again so I put the carb back on and tried starting the car again. It cranked, but now has an off idle stumble. The carb nozzles drip fuel when pumping the accelerator lever. The car would start back up and idle continously while hot. The car would not start after I let the car sit for a few ours to cool down. The accelerator pump lever was once again in a bind.

What could be causing the accelerator pump lever to bind up?

the rubber accelerator pump material has been attacked by the alky in the gasoline. replace it with a newer material one. they are blue or green in color not black

[Bryan M.]

Re: LT-1 Holley Carb Problem Help

the rubber accelerator pump material has been attacked by the alky in the gasoline. replace it with a newer material one. they are blue or green in color not black

Thanks Clem.

What do you use to loosen those funky looking screws on the accelerator pump cover?

[Joe C.]

Re: LT-1 Holley Carb Problem Help

Thanks Clem.

What do you use to loosen those funky looking screws on the accelerator pump cover?

If they are clutch heads or Torx heads, then use a small slotted screwdriver.

[Bryan M.]

Re: LT-1 Holley Carb Problem Help

If they are clutch heads or Torx heads, then use a small slotted screwdriver.

They look like clutch screws. Me thinks, I'm going to have to break out the grinder and modify a screw driver.

[Stuart F.]

Re: LT-1 Holley Carb Problem Help

Bryan;

Invest in a small set of Torx Head screwdrivers. You'll be glad you did as you will run into Torx head screws more and more. I love them. If I had my way, I'd like to see Obama decree that all Phillips Head screws must be replaced by Torx Heads w/i 4 years. It would be one thing he could do to make our lives happier.

Sorry for your Holleyitis. There's another thing we could do without; Holley carbs.

Stu Fox

[Bryan M.]

Re: LT-1 Holley Carb Problem Help

Bryan;

Invest in a small set of Torx Head screwdrivers. You'll be glad you did as you will run into Torx head screws more and more. I love them. If I had my way, I'd like to see Obama decree that all Phillips Head screws must be replaced by Torx Heads w/i 4 years. It would be one thing he could do to make our lives happier.

Sorry for your Holleyitis. There's another thing we could do without; Holley carbs.

Stu Fox

Stu,
I do have a set of the Torx screw drivers, but they will not fit the screws on my carb. The screws slots are kind of oblong.

I checked on-line for Holley parts availability and it appears that the Holley parts are pretty common to the local parts stores. I'm going to pick me up an accelerator pump today.

[Clem Z.]

Re: LT-1 Holley Carb Problem Help

they are 5/32" clutch head screws and sears still sells those screwdrivers

[Tim S.]

Re: LT-1 Holley Carb Problem Help

A few years ago, I purchased some clutch head screwdrivers from Snap On. While I use them VERY infrequently, it beats messing up a fastner. They can be hard to find otherwise.

As far as your running problem, I would also check how tight the fuel bowls are after a few heat cycles. If the metering blocks have some warp to them (as many do), it can have a noticable effect on idle quality. While your carb is off, I would install all new gaskets and only use a kit from Holley. The gaskets are better than standard parts store variety and they stand up to the alcohol in the fuel.

Best of luck!
Tim

[Bryan M.]

Re: LT-1 Holley Carb Problem Help

they are 5/32" clutch head screws and sears still sells those screwdrivers

I needed an excuse to run by Sears. Should be a sale on today!

A few years ago, I purchased some clutch head screwdrivers from Snap On. While I use them VERY infrequently, it beats messing up a fastner. They can be hard to find otherwise.

As far as your running problem, I would also check how tight the fuel bowls are after a few heat cycles. If the metering blocks have some warp to them (as many do), it can have a noticable effect on idle quality. While your carb is off, I would install all new gaskets and only use a kit from Holley. The gaskets are better than standard parts store variety and they stand up to the alcohol in the fuel.

Best of luck!
Tim

Advanced Auto shows Holley kits in stock. I'm going to check'em out on the way to Sears.

The one thing I found out is the fuel pump seems to be the correct one on the car. The number on the flange is 29K40956.

[Jim T.]

Re: LT-1 Holley Carb Problem Help

Holley Renew and Holley Trick Kits are not inexpensive and one day you will eventually use the parts. Holley packages fuel bowl gaskets, power valves, metering block gaskets, and floats sold in blister packs.
Might be an avantage in also changing out the needle and seat since it is apart.

[Larry M.]

Re: LT-1 Holley Carb Problem Help

Bryan and others:

Tru-Value Hardware stores stock and sell the clutch-head screw drivers. "Master Mechanic" Brand, Item # 367169. Made in USA. Screwdriver handle may also say CL532.....don't know what this means.

Also, Long Island Corvette Supply sells the clutch-head screwdriver in the TOOLS Section of their catalogue.

Larry

[Clem Z.]

Re: LT-1 Holley Carb Problem Help

Bryan and others:

Tru-Value Hardware stores stock and sell the clutch-head screw drivers. "Master Mechanic" Brand, Item # 367169. Made in USA. Screwdriver handle may also say CL532.....don't know what this means.

Also, Long Island Corvette Supply sells the clutch-head screwdriver in the TOOLS Section of their catalogue.

Larry

the 532 stands for 5/32" the size you need

[Larry M.]

Re: LT-1 Holley Carb Problem Help

the 532 stands for 5/32" the size you need

Thanks, Clem. Now it makes sense.

Larry

[John H.]

Re: LT-1 Holley Carb Problem Help

Corvette Central also sells a set of clutch head screwdrivers (5/32" to 5/16") to fit all the different sizes of them used on C1's; have had mine for many years.