This article will cover the basic removal and replacement of the Quadrajet Carburetor found on 1967 and latter Pontiac’s. Rebuilding and restoring a Quadrajet should be left to a professional. Removal and replacement can be done with a few simple tools.
Removal of your Pontiac Quadrajet Carburetor
Take pictures and make notes of how all connections are made. Look at the choke to see if it is remote or has a hear riser from the intake manifold. The heat riser type only slides in the bottom and may require the removal of the box to reattach. Some latter models had an electric choke, a wire will have to be marked and removed.
Mark the throttle spring and all of the vacuum lines with location.
Disconnect the inlet fuel line with a wrench on the line and one on the filter nut. Use a line wrench on the fuel line to keep from rounding the nut on the fitting.
After making sure there are no other lines or wires attached to the carburetor, remove the four nuts or bolts holding it to the manifold.
Parts to check and move from one carburetor to another.
The hold down bolt for the air cleaner, vacuum fitting at the rear and the throttle linkage adapter will have to be moved from one carburetor to the other. Most of this will be easy, the bolts for the throttle linkage should only be replaced the way they were on. The throttle may not open all the way if the bolts are on backwards.
Most rebuilt carburetors will come with a new base plate and gasket for the air cleaners.
Installation of the Carburetor
Place the rebuilt Carburetor on new base gasket and hand tighten the four bolts or nuts. Check for throttle movement, make sure all open all the way and there are no obstructions to hamper operations of full throttle. Tighten to 9 foot pounds of torque. Over tightening will warp the fuel bowl causing leaks or rough running.
Check the Fuel Filter nut for tightness. Hold this nut with a wrench while attaching the fuel line, this will cut down on leaks and keep you from stripping out the threads in the fuel filter.
Replace the rod for the choke if equipped. If Electric choke replace the wire connection.
Re-install all vacuum hoses, Automatic trans, Distributor advance and Power brakes.
Hook up the throttle cable, return spring and make sure when the pedal is on the floor, the throttle opens all the way. Some adjustment may be needed as carpet sometimes keeps the throttle from opening all the way.
After everything is tightened up, you can start the motor with some help. You will have to crank the motor a few time to fill the float bowl. Have someone checking for fuel leaks and loud vacuum noise when the engine first starts. Check the operation of all of the vacuum operated equipment to ensure each item is working properly before heading out on the first drive.
Happy motoring with your muscle Pontiac!