Quadrajet Carberator

[Steve341]

Grrr This truck is really starting to get my goat now. I got that 75 C20 Scottsdale camper special  with the 454, as you guys have helped me with its hesitation problem. Thought I got the truck running perfect just by changing the small fuel filter in the carb, and the main one under the truck. I drove it around lots in the past 3 days, drove it HARD and no problems at all. Got the truck box camper loaded in the back, a 3200 pounder dry weight I may add that has been on that truck since it was brand new I've been told. It is a 1974 Scamper 12 footer. Heavy unit. Anyways loaded it up in the truck box, took it for a spin slow speed working fine leaving town. I took it on the highway and put er to the mat, still fine. And about 3 minutes into our little test drive as I wanted to see how this beast would yard this camper no problem of course and I have never driven with it on, wanted to see what it was like, it hesitates, I back off on the gas pedal, floor it again and then she quits on me. Tried starting it again, nothing not even a fire, before we got out of the cab. Real STRONG gas smell thought it was coming from the back of the truck, no. Popped the hood up and the carb is soaked in gas and a nice pool of fuel on the intake sizzling away. Called the guy I bought the rig off of, he came down and checked it out. Appears the choke was stuck open and he could not get it to close. He said he would hold it closed and go in and try cranking it over so I did and we had a small fire, thankfully had a fire extinguisher in the camper. Then he just pulled it back home with his tundra. Is it time to rebuild or replace the carburetor? He said he would get a rebuild kit and fix it up.

[Stewart G Griffin]

How soon do you need the truck?

[Steve341]

Last weekend in may

[Jason S]

What you describe, sounds like the float may be hanging up. 

If the truck has just sat for a while, in my opinion, I'd clean and put in a rebuild kit to the current carburetor.  If there were not any major issues with the original carburetor beforehand, other than the truck having set for a while, I would just clean the carburetor thoroughly and install the new gaskets; I would check the float setting and other adjustments, but wouldn't touch them at the time of rebuild. 

[Steve341]

The carb number is 7045212. I was messing with it today. It's spraying fuel straight up the choke above the primaries.

[Steve341]

I got the carb off the motor. Going into Edmonton see if I can find a rebuild kit

[74 C-10 Shorty]

I suggest this manual it has a lot of information about the Q-Jet..

http://www.cliffshighperformance.com/buy_book_2.html

[popsthebuilder]

Are you sure it's the carb? have a similar problem w/ mine every couple of months. No resistor for the coil. I still have points ignition. w/ out the resistor the coil goes out every couple of months. Even w/ choke problems it should at least fire.  If you have converted to hei then disregard.

[Jason S]

If you have converted to hei then disregard.

1975 C-20 should have HEI from the factory.

[Steve341]

I bought a remanufactured Quadrajet. It is not a Rochester, its a Carter same thing though. I put the carb on, didn't take too long. Set the idle took it for a spin and it preformed just great. The next day I started messing with the air mixture screws. Yesterday my dad wanted to take it for a rip. So it is extremely windy and I'm packing a truck camper in the box so we had to open it up going into a 40 mph wind. Here we go. Sputtering yet again. Fuel pump seems to be fine, its not leaking or anything like that. Now what could be the problem? Reman carb on it, and its acting up again, but this time the carb is not leaking like the old one was.

[Steve341]

I bought a remanufactured Quadrajet. It is not a Rochester, its a Carter same thing though. I put the carb on, didn't take too long. Set the idle took it for a spin and it preformed just great. The next day I started messing with the air mixture screws. Yesterday my dad wanted to take it for a rip. So it is extremely windy and I'm packing a truck camper in the box so we had to open it up going into a 40 mph wind. Here we go. Sputtering yet again. Fuel pump seems to be fine, its not leaking or anything like that. Now what could be the problem? Reman carb on it, and its acting up again, but this time the carb is not leaking like the old one was.

It's Points

[Steve341]

On the plus I only have to pump it 1-2 times to start at cold instead of 30-40 lol

[74 C-10 Shorty]

I bought a remanufactured Quadrajet. It is not a Rochester, its a Carter same thing though. I put the carb on, didn't take too long. Set the idle took it for a spin and it preformed just great. The next day I started messing with the air mixture screws. Yesterday my dad wanted to take it for a rip. So it is extremely windy and I'm packing a truck camper in the box so we had to open it up going into a 40 mph wind. Here we go. Sputtering yet again. Fuel pump seems to be fine, its not leaking or anything like that. Now what could be the problem? Reman carb on it, and its acting up again, but this time the carb is not leaking like the old one was.

Sorry, Rochester and Carter two different animals, could be jetting but I'm betting on weak ignition...

[Steve341]

GM Contracted out Carter to produce the Quadrajet as Rochester could not keep up on demand.

[Steve341]

GM Contracted out Carter to produce the Quadrajet as Rochester could not keep up on demand.

I am leaning towards weak ignition as well. Sorry it is HEI there is no ignition coil at all. I never thought of ignition problems. I was about to order a new fuel pump, but I am told these mechanical ones either work or don't work or are leaking when they are failing. HEI, Wires, Plugs? What kind of cost am I looking at? Big Money for the HEI coil I bet