quadrajet 455ho

[gearhead63]

hi working on pontiac 455ho stock eliminator with a single booster quadrajet that runs fat in first gear from 5100 -5900 afr 11-11.5 anyone know how to fix this. regards magnus

[Hacksaw]

May be over rich with the secondary metering rods. The smaller the diameter of the rod the fatter you will be.

[gsa612]

How is the carb set up,does it have primary rods and jets with the spring or just jets with no rods.Where's the float level?,fuel pressure?. gsa612

[gsa612]

I just noticed it was a single booster carb.I believe it's only legal on a few cars yours being one of them.The guy you need is Danny Ashley,he's a member here,hopefully he'll see this.I don't have any current contact info,maybe someone here does. gsa612

[ss3011]

There is a special system that the 1971 455 HO carb has , its called the POE system . Its purpose is to add extra fuel at WOT . You may want to get the Quadra Jet book by Cliff Ruggles , he has a section on that system . Most Q-Jets do not have that system , it doesn't meter fuel as well as having fuel go through the venturies . You say your engine only runs rich in 1st gear , are you running a Ram Air hood and air cleaner ? Which body style , GTO , Formula , or Trans Am ? Each has a different system .

Check Fig 11 https://www.gmcmi.com/wp-content/upl...ice-Manual.pdf

[bob3240]

May be sloshing fuel out of the secondary metering rod holes. Do you have them sealed with tape or anything?

Originally Posted by gsa612

I just noticed it was a single booster carb.I believe it's only legal on a few cars yours being one of them.The guy you need is Danny Ashley,he's a member here,hopefully he'll see this.I don't have any current contact info,maybe someone here does. gsa612

Danny is retired and living the quiet life, have to find somebody else.

[rod butcher]

Try Dean Oliver #870-830-5470

[gearhead63]

the car is a 1972 lemans no ramair hood no aircleaner no primary rods just jets secondary metering rod holes are sealed float level 1/2 in fuelpressure 6psi accelerating well tubes are blockt afr 12.5-13.5 in second and third gear. regards magnus

[ss3011]

Originally Posted by gearhead63

the car is a 1972 lemans no ramair hood no aircleaner no primary rods just jets secondary metering rod holes are sealed float level 1/2 in fuelpressure 6psi accelerating well tubes are blockt afr 12.5-13.5 in second and third gear. regards magnus

Was the float level and the accelerator well tubes modified that way to try and fix this rich problem ? Not sure what you are talking about when referring to accelerating well tubes . Are these the tubes that are supposed to feed fuel into the secondaries as the flaps start to open ? Also when you are on the 2 step , are you flooring the accelerator pedal ?