You can buy a kit with new jets and metering rods for this purpose. Quadrajets can be a little tricky, so you might want to get a how-to book and read up on the procedure.
Yes. There are books dedicated to the Rochester Quadrajet.
This depends if it is on a carbureator or on fuel-injection. On a carbureator, locate the idle adjustment screw and turn until idle is satisfactory.
You don't. You take it to a museum because a 233 year old truck deserves to be in a museum.
If it a Rochester carberator, there is no mixture adjustment. That is an internal setting done when the carburetor was put together or at the time of rebuilding. The only adjustments you can make is to the idle and choke I have a 93' 2500 vandura and It failed smog and I advanced the Timing a tiny bit and it passed....yaaaaay
it depends if it is wet then you will need to go to the dealership and get the factory spark plug and if this is not the problem take it to a shop to get it checked out or change and adjust the carbureator so that water or something doesnt get in there.
Bend the tab that contacts with the "needle". But DON'T put pressure on the needle when you do so. Carburetor rebuild instructions that come with the carb rebuild kit will tell you how to adjust everything and give optimum float level settings.
run some sea foam through it and some mid grade gas through it sounds like your carbureator is gummed up if that doesnt work take it to an authorized dealer and have them adjust your air fuel and oil mixture cost about sixty dollars or so.Type your answer here...
At the top rear passenger side of the carb there is a setscrew locking a spring adjustment that goes to the vacuum butterfly on the sceondary. the spring is only adjustable 1 turn. A slotted screwdriver is used to turn the spring adjuster after you loosen the Allen screw. http://image.carcraft.com/f/9793801ccrp_0801_02_z+muscle_car_tech_tips+quadrajet_adjustment.jpg
Yes and no.. How bad do you really want to change it? Most vehicles with this TBI setup are computer controlled. To change the mixture you will need to LIE to the computer. This means altering the info from sensors such as the o2 sensor. You can do nothing with the TBI unit itself to change the mixture.
The future tense of adjust is will adjust.
adjust
adjust