Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor
Recipe #1 sucking fuel from boosters
oktorque:
17059272 I installed Cliff's kit and used his restrictions for idle down and main bleeds in air horn. I'm using Cliff's recipe #1 from his book. At first I could not get it to run. Then I opened the mix holes and can now idle, but is drawing fuel from boosters and surging from 16.5 to 18hg vacuum. I interpret surging as a sign of lean.
I'm going to open the idle tubes from 36 to 44, and the down restrictions to 54. If that does not sound correct, please advise.
oktorque:
I went back through Cliff's book and confirmed my suspicions that indeed the idle system is too restrictive and it is pulling fuel from the boosters just to stay running. Tomorrow I shall open each, the idle tubes, down restriction by .005, and I'll open the mix holes to .090.
Depending how it runs once the changes have been made, I'll plan the next course of action.
oktorque:
I haven't made the changes yet. I just wanted to add that I'm surprised recipe #1, which is for a 350 v8, unless I misread, would not be enough fuel at idle for a ford 300 I6. Yeah, okay, it does have the hp of a 360.
oktorque:
I NEED A BIT OF HELP.
I opened the main in the air horn to 72, the upper idle bleed to the same, and the lower to the same. I opened the mix holes to 90. It helped. But it still chugs when put in gear at idle. It pings badly when I get on it. I'm using 71 jets with 41p rods. Float is set about 3/8".
Cliff Ruggles:
If you are lacking idle fuel do NOT open up any idle airbleeds. They were already the right size on that carb stock.
No need to touch the main bleeds either, the uppers are slightly too big, and lowers too small, but they average out correct without modifications on that carb number.
The first recipe is for small cams and high vacuum at idle. If you have a larger than stock cam you will need larger idle tubes and may have to open up the DCR's a bit.
Make very small changes, most likely you'll not need more than .038" idle tubes in that carb, and .055" DCR's, but I'd have to know the engine specs to make specific recommendations?.....Cliff
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