I have a 70 W31 engine with the original quadrajet carb.When dyno tested the A/F readings were ranging from 7 to 9. Just a bit rich.Any suggestions (except from Norm) would be appreciated.Thanks.

 

Gotta check a bunch of stuff, the bowl plugs, they normally leak, fuel pressure, yes the primaries do have metering rods, are they sticking etc. Needle and seat, good condition, set right? If possible try another carb on it. Or you maybe have to send it out to a more competent rebuilder. Good luck!

 

W31 shouldn't have primary metering rods, unless everything the factory put out about them is a lie...

Are these A/F readings at WOT or thruout pull range?

 

Sorry guys, every Quadrajet I've ever seen had primary metering rods. My mistake.

 

It probably doesn't interest too many,but, on runs three days apart, the following results were obtained.On the first day the readings ranged from 11.4 to 14.0. Three days later (same secondary rods and same hanger) it ranged 7.8 to 9.8 with rpm range from 3000 t0 5500.
His explanation was different atmospheric pressure or air density or maybe tooth fairy dust. I'have to believe that his test instrumentation needs calibrating/overhauling! Any comments welcome.

 

I agree. At around 8.0 to 1 air/fuel I'm pretty sure it would have been belching black smoke. May want to try someone else, at the very least different equipment.