Quadrajet Problem Solving > Dialing in your rebuilt Quadrajet carburetor

Poor Fuel Mileage on 4.3 V6 with Quadrajet 17056250

<< < (4/15) > >>

don3194:
Thanks again Cliff, I have a friend I'm going to sell the Marine Quadrajet to as a spare for his boat. I found a 7043202 Quadrajet for very cheap and just picked it up. I know you said 79 and up but I just got it on a whim hoping it could be converted to e-choke. Just wanted to ask if this carb can be converted.

Cliff Ruggles:
No, the choke is on the intake manifold.

There are a few "conversions" available.  One involves replacing everything on that side of the carb with a modified bracket/e-choke, and the other uses parts from a 70-74 Olds or 73-74 Pontiac and the main casting has to be drilled/tapped for the pull-off bracket.

I've seen a third using a modified 75-up adjustable choke pull-off and putting a later hot-air choke housing on the side of the carb.  I'm not fond of any of those and it would be a LOT easier and less expensive to just source out a later model hot-air or electric choke carb right to start with.....IMHO.....

Kenth:
To properly evaluate any carb it has to be at least renewed to factory specs.
Then it may need some help due to any symptoms shown at test drive.
A 4.3 Liter engine pulls less air than a 350 cui and the vacuum signal will be weaker making the power piston(s) rise at smaller pedal movements.
In the 17056250, early 1976 Olds 350 unit, the auxilary power piston spring is longer and stiffer than the regular power piston spring and may add more fuel than nessecary too early at low speed city driving for you 4.3 L.
The first attempt would be to use a weaker auxilary power piston spring, or cut to the same length as the regular pp spring.
I have done quite a few of these units, most of them got the auxilary pp system eliminated, 3-48 screw in jet and plug piston bore. APT is seated to start with and main air bleeds i bowl opened to .070". Most times #76-#77" jets with 52M rods are used. You always have the option to fine tune the APT. Also, an electric choke element makes the carb independent of intake styles.
HTH

don3194:
Thanks again Cliff, I think I'll just go ahead and resell what I bought. Also thanks Kent, I'll try and see if I can make a lighter spring for the auxillary power piston, otherwise I am interested in possibly eliminating it all together. Are you aware of any other threads with more information on eliminating the auxillary power piston?

Cliff Ruggles:
The aux PP and aneroid located APT carbs were short lived and for good reason.

Without going into great detail here I would NOT use one and source out a later APT model instead.

The 1975/76 models with that system just don't work well compared to the later models even after you block off the aux PP and single jet in the bottom of the casting.

I am NOT saying that you can't make one work, but it will never work as well anyplace as a later model set up with tapered metering rods that you can precisely position in the jets......FWIW......

Navigation

[0] Message Index

[#] Next page

[*] Previous page