quadrajet 455ho
 

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

Re: quadrajet 455ho
 

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

Re: quadrajet 455ho
 

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

Re: quadrajet 455ho
 

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

Re: quadrajet 455ho
 

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

Re: quadrajet 455ho
 

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

Re: quadrajet 455ho
 

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

Re: quadrajet 455ho
 

Try Dean Oliver #870-830-5470

Re: quadrajet 455ho
 

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

Re: quadrajet 455ho
 

What size jet in the primary? Are you leaving off the two step, and does the condition get better with rpm? Sounds like it may be rich from being on the two step then clears up after.