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Dialing in your rebuilt Quadrajet carburetor / Re: Qjet 17057253 on a 380 Olds stroker
« Last post by Cliff Ruggles on Today at 04:49:47 AM »A little warp is normal and fine provide the parts seal up effectively.
Considering the symptoms and issues you are seeing, I suspect a fundamental issue with the carburetor someplace not related to how it's set up.
For example, you mention increasing throttle angle/engine load and going lean. By design that scenario will bring in MORE fuel.
Next time you have the engine running remove the air cleaner and get up over the carb enough so you can see into the primary side. Move the throttle quickly and you will see a nice shot from the accl pump and well atomized cone spray of fuel coming from the venture areas. This is adding more fuel, not less.
The same thing happens when you drive the vehicle, but it also brings in additional fuel at low throttle openings from the transfer slots above the mixture screws. There is no scenario that I've seen where less fuel would be delivered with any significant increase in throttle angle and engine load.
I also use basically the same carburetor (1977 Pontiac) which differs the most in having a large front vent tube in the airhorn. It is set up very close in specs to yours and uses .073" main jets and out tapered .044" primary metering rods.
It has powered 4 different engines to date with the same basic arrangement. The current engine is well over 550hp/600tq and it brings in plenty of fuel for "normal" driving and increases fuel delivery with any increase in throttle angle/engine load.
Maybe changing the airhorn on your carb is part of the problem, or something else not quite up to par someplace? When you use good parts, the correct settings, and don't get acceptable results it's time to look a little deeper at things to find the problem(s).........Cliff
Considering the symptoms and issues you are seeing, I suspect a fundamental issue with the carburetor someplace not related to how it's set up.
For example, you mention increasing throttle angle/engine load and going lean. By design that scenario will bring in MORE fuel.
Next time you have the engine running remove the air cleaner and get up over the carb enough so you can see into the primary side. Move the throttle quickly and you will see a nice shot from the accl pump and well atomized cone spray of fuel coming from the venture areas. This is adding more fuel, not less.
The same thing happens when you drive the vehicle, but it also brings in additional fuel at low throttle openings from the transfer slots above the mixture screws. There is no scenario that I've seen where less fuel would be delivered with any significant increase in throttle angle and engine load.
I also use basically the same carburetor (1977 Pontiac) which differs the most in having a large front vent tube in the airhorn. It is set up very close in specs to yours and uses .073" main jets and out tapered .044" primary metering rods.
It has powered 4 different engines to date with the same basic arrangement. The current engine is well over 550hp/600tq and it brings in plenty of fuel for "normal" driving and increases fuel delivery with any increase in throttle angle/engine load.
Maybe changing the airhorn on your carb is part of the problem, or something else not quite up to par someplace? When you use good parts, the correct settings, and don't get acceptable results it's time to look a little deeper at things to find the problem(s).........Cliff
? not clear on this)