Thread: Help, I am ready to give up!

Tweet

fuel 5-8 lbs should be fixed

Put a stock pump on and try it.

power valve was the first thing i replaced, even tried running a plug in the secondary metering block, it had no effect whatsoever

Keep us posted on what the problem was, thanks Kurt

R Pope has given you the cheapest, easiest and quickest fix.
"Put a stock pump on and try it."

Even cheaper---just disconnect the line to the carb and plug---if it clears up you have found the problem--

I have used this numerous times to prove that domeone had too much fuel pressure

if your runing that big cam 588/588. 274 @050 and 107 lca that 6.5 PV is to big should be a 2.5 or a plug if a plug jump up about 10 jet sizes up and the carb is small for your engine so i would bet with that cam you have your idle turn up past you idle circuit so you will have to crack the back barrels so you can get the idle circuit to work

The motor is producing 10-12in. of manifold vacum at idle, I tried a 4.5 power valve without any change at all. I have the factory specs on the carb, and they show no pwt valve in the secondary block w/ 70 jets front and rear. It did clean up the mid range throttle response when I eliminated the secondary pwr valve. I am still having no success getting the motor to idle without severely loading up. I am trying to locate another carb to compare results, and eliminate the possibilty of an ignition problem, The msd components have all checked out ok, but I am not ruling anything out.

try another carb

Did you get the fuel pressure adjusted???? That small of a carb, maybe some bleed holes in the throttle blades????? Think the fuel pressure has to be correct before the carb will work right.....

a few questions

Exactly what number holley carb do you have?
Is it new or has it been rebuilt or altered?
are you running an aircleaner?

What is you timing set at and is you timing marks/cam/tdc all checked and proven????

Does your throttle blades have holes drilled in them?

How far open are the throttle blades front and secondary???

Why are you trying to run so much fuel pressure?

What type float bowls and floats are on your carb???

pull the front float bowl and jet plate put a straight edge on carb body from from screw hole to screw hole in an x pattern many times people over tighten the float bowl screws this causes the carb body to bend, and the gasket to not clamp in the center where the power valve is causing an internal vacuum leak it takes vacuum to overcome the spring in the power valve. if this is the case cut a peice of heavy glass about 1 1/2 in x 8in long wrap some fine wet and dry sand paper around it with solvent or wd 40 surface the carb body until you have full contact I keep apeice of glass in my tool box and do this to every holly carb i work on you will be amased at how many you find with that problem it saves alot of problems then dont overtighten the screws. also check the jet plate and make sure the vacuum passage to the power valve well is not blocked some times sombody used the wrong gasket blocking the vacuum holes holly carbs are very simple contraptions its amasing the work as good as thy do there is no magic here its not rocket science dont let it intimidate you well thats my 3 cents worth ......ted

I like that i didnt even have to read 1/3 of the page before I saw it has already been answered. Fuel Pressure Fuel Pressure Fuel Pressure. Edelbrock carbs take a MAX of 6.5PSI. I run mine at 7psi and end up with a rich idle with everything leaned out all the way.. if your running 10 on anything thats just.. wow.

Call Holley or look in the instructions for your carb and find out what they say to run for max pressure and run THAT. NOT HIGHER OR LOWER. DO NOT BE LIKE ME AND RUN .5 PSI HIGHER. BAD IDEA. IM TOO COOL FOR RULES, YOUR NOT.

HOLLEYs will take abit more fuel psi then the old afb or edelbrock they do not like hi fuel psi they will FLOOD

Originally Posted by jerry clayton

a few questions

Exactly what number holley carb do you have?
Is it new or has it been rebuilt or altered?
are you running an aircleaner?

What is you timing set at and is you timing marks/cam/tdc all checked and proven????

Does your throttle blades have holes drilled in them?

How far open are the throttle blades front and secondary???

Why are you trying to run so much fuel pressure?

What type float bowls and floats are on your carb???

list#0-80540-1 Model#4150hp, I bought the carb with a broken baseplate on e-bay, I have been thru the carb, replaced the baseplate with the factory part# baseplate, and all new parts throughout. I am running a 14"x4" K&N filter, initial timing is set at 12 degrees with total timing at 32 degrees I am running a fluidamper, and have personally degreed the camshaft myself. The throttle blades are all four drilled and the curb idle set primary, and secondary together, I am just running the pump pressure from a holley high volume mechanical fuel pump, which has never before been a problem with other holley carbs. I will get a regulator to get the pressure down, but have not as of yet.