Some issues with a friends 4150 Holley. When we started the car this spring fuel was running in from the secondaries and kind of flooding. Seems that is solved, Gummed up needle and sticky float.
While working to get that issue solved, we noticed that the secondaries do not appear to ever open. Shaft and everything is free by hand. It is a 79 Holley with an electric choke, so we haven't pulled that off to get the diaphragm off.
Just wondering what likely might be the problem? We put some tape around the shaft that should have pulled up and thus disturbed the tape when we ran the car out around the block a few times at WOT. But the tape is undisturbed. At what rpm should the secondaries open or should they open as soon as we go to WOT. So it doesn't appear the secondary throttle plates are opening.
Tony Hoffer said
May 16, 2011
what sized carb and what are the specifics on the engine... Maybe the diaphragm is torn.
jim larson said
May 16, 2011
Tony Hoffer wrote:
what sized carb and what are the specifics on the engine... Maybe the diaphragm is torn.
We were thinking about a torn diaphragm or stuck check ball ; but its kind of a hassle to take off because you have to take the electric choke off first. So I thought I'd ask if anyone had any other suggestion.
The engine is a chevy 350 with an 65ish corvette intake and a holley 4150 with the secondaries operated by the diaphragm. Don't know what the cam is or the volume of the carb, guessing 650cfm or more. I think the number is 2318 and date is from a year ending in 9, I am guessing 1979. I believe the trans is a 350 and the car is a 40 ford.
jim larson said
May 16, 2011
Runs good, just had a ride in the car this afternoon. Secondaries just not opening.
Some issues with a friends 4150 Holley. When we started the car this spring fuel was running in from the secondaries and kind of flooding. Seems that is solved, Gummed up needle and sticky float.
While working to get that issue solved, we noticed that the secondaries do not appear to ever open. Shaft and everything is free by hand. It is a 79 Holley with an electric choke, so we haven't pulled that off to get the diaphragm off.
Just wondering what likely might be the problem? We put some tape around the shaft that should have pulled up and thus disturbed the tape when we ran the car out around the block a few times at WOT. But the tape is undisturbed. At what rpm should the secondaries open or should they open as soon as we go to WOT. So it doesn't appear the secondary throttle plates are opening.
We were thinking about a torn diaphragm or stuck check ball ; but its kind of a hassle to take off because you have to take the electric choke off first. So I thought I'd ask if anyone had any other suggestion.
The engine is a chevy 350 with an 65ish corvette intake and a holley 4150 with the secondaries operated by the diaphragm. Don't know what the cam is or the volume of the carb, guessing 650cfm or more. I think the number is 2318 and date is from a year ending in 9, I am guessing 1979. I believe the trans is a 350 and the car is a 40 ford.
This is on our website "Tips & Tricks" - http://www.bob2000.com/carb.htm
Well worth the reading. Once you've exhausted the diagnostics and "Try this's" on here, then think about rebuilding the carb.
Thanks John, the site is really informative.