Quadrajet help..

[GMCjunkie]

Ive been running a Rochester Quadrajet on my Burb since I bought it, and it has performed basically flawless, until lately. Before I had my engine swapped, it seemed like it was acting up so I had it rebuilt (supposedly)...Well its still not right, when its cold, its REALLY hard to get er started,,, seems like it cant keep enough gas in the carb to get it runnin til you pump and pump..... Im told it has "something" to do with the choke, and one is telling me I may "need" to go to an electric choke, another is telling me I may "need" to go to a manual choke... Why would I "need" to do either?? Why cant my carb just be fixed to work like its supposed to. I dont understand what theyre telling me, (mabey thats the idea)...I know absolutely NOTHING about carbs, and Im sick of paying people to "fix" things... ANY help would be much appreciated.

junk

[WORNBRAKES]

Hi there Junkie. If your Q-jet is like mine it uses what I call automatic choke. It has a plate with the coil that screws to the intake manifold and a rod that connects it to the carb. This is on the pass side. If you replaced the intake during the engine swap, the manifold you now have may not be for this style choke. Then you would have to go to either a manual or electric one. If it is designed for this choke, you can replace it. Only cost about 5 dollars at just about any part store. I have to replace mine every 6 monthes or so. I hope this helps a little.
Mario

[pierce]

Exactly like Wornbrakes says, you can check to see if it's working...when it's cold. The rod on the pass side should be holding the flap on the carb closed because the coil is contracted, pull down on the rod to see if there is any play. When the motor warms up the coil heats and pushes the rod up to open the flap on the top of the carb.

[Mike C]

At some point in its life, a basic rebuild will not suffice. Throttle shafts get worn and need to be rebushed. I put a JET Q-jet on both of my trucks. The ONLY drawback to the JET IMO, is the price. $359 from Summit for the Stage II. They are completely R&R and have epoxied wells to help prevent leak down and come with an electric choke. Easy hook up in my '72 Jimmy with throttle cable, but I had to make a throttle arm for the mechanical carb linkage in my '70. Both trucks start really easily, idle really well, and mileage improved significantly. (nearly 20% in both if 11 to 13 is significant in the truck and 12 to 14 in the Jimmy.) I have run two different Holley 600s, the stock Q-jet, and a Holley 780 in addition to the JET, and while overall power may be slightly higher with a Holley, driveability is WAY better with the Q-jet. I would buy another JET in a heartbeat, but eventually mine will give way to a complete TPI setup (it's already on the shelf!)

[6869704X4]

As cold as it is now, when you set the choke it should close all the way.
Another possible is your accelerator pump. Are you getting a good strong squirt out of it? On both sides? An additional symptom of accel pump problems is a hesitation or stumble when you hit the gas to accelerate. This may not happen if your carb is jetted rich though.
Can you post a pic of the choke setup? Maybe we could tell if its hooked up right.

I was up in your "hood" saturday. Had to drag some furniture up to Cairo.

[72LNGHRN]

I HAD A SIMILIAR PROBLEM BEFORE I JUNKED THE QUADRAJET MINE WAS THE ACCELERATOR PUMP WOULDNT GET ENOUGH FUEL TO STAY RUNNING. IT'S ALSO EASY TO REPLACE, AND CHEAP.

[neonlarry]

http://www.carbs.net/quadrajet.asp This place sells an electric choke that will work with the q-jet with the divorced choke, but, as long as the choke type that you have is working right, I doubt the chpke is the problem. The electirc choke would probably work better, but if there is some other problem it won't fix anything.