the quadrajet on my 85 likes to randomly start flooding itself going down the road, itll run great then act like its starving for fuel, but you can see black smoke coming out the exhaust, when you open the hood and look at the carb, you can see fuel dripping off the electric choke solenoid. ive taken the top plate off and the float isnt stuck or sunken. the needle and seat are clean and clear of debris, all of the metering rods look good, i used some very fine grit sand paper and rubbed them a little bit. i found a deal the other day, i got a brand new quadrajet. that hasnt even been mounted before, its not rebuilt. for $50 but the problem is its for a 1980 pontiac. it looks like it would bolt to the intake manifold, but it doesnt have all the vacuum ports the one on my engine does, and the choke setup is different. can anybody help me? i would like to put the new carb on there if i can but if not should i put the parts from the new carb in my old one? thanks in advance
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Carb Question
- Thread starter 1985CK5
- Start date
Black smoke out of the exhaust means you're running WAY rich.
Fuel dripping off of the choke solenoid doesn't sound right to me but I've never messed with a Q-jet that had an electric choke.
Is this the original motor with the original carb? Have the metering rods and/or jets ever been messed with?
A different Q-jet that came from a different motor will not work well on your motor; for instance, the Q-jet that came on my truck was tuned to work at 6000 ft. elevation on a 350. The Q-jet that came on a 454 at 50 ft. elevation will be very different.
You can almost never throw a carb on a motor and expect it to work correctly. You will have to tune it to get it to work right unless you're switching them amongst identical motors.
The 1980 carb probably uses the hot air choke which has a coil that expands/contracts based on temp to control the choke. Most OEM intake manifolds of the time have a provision for this, not many aftermarket ones do. Your best bet here is to go to a manual choke or just deal with a wide open choke all the time (which, IMO, is the better way to go for any temps above freezing).
Fuel dripping off of the choke solenoid doesn't sound right to me but I've never messed with a Q-jet that had an electric choke.
Is this the original motor with the original carb? Have the metering rods and/or jets ever been messed with?
A different Q-jet that came from a different motor will not work well on your motor; for instance, the Q-jet that came on my truck was tuned to work at 6000 ft. elevation on a 350. The Q-jet that came on a 454 at 50 ft. elevation will be very different.
You can almost never throw a carb on a motor and expect it to work correctly. You will have to tune it to get it to work right unless you're switching them amongst identical motors.
The 1980 carb probably uses the hot air choke which has a coil that expands/contracts based on temp to control the choke. Most OEM intake manifolds of the time have a provision for this, not many aftermarket ones do. Your best bet here is to go to a manual choke or just deal with a wide open choke all the time (which, IMO, is the better way to go for any temps above freezing).
its the original carb i think, but it has a 350 in it. it came with a 305. i have really no idea if theyve ever been messed with i just got it. i dont see anything wrong with it,, but im not very familiar with carbs. would using the parts from the other carb be the way to go?
First, figure out the fuel leak near the choke solenoid. It shouldn't be doing that.
After that, clean the plugs and drive the truck for a while. Then pull the plugs again. If the porcelain is black or brown, its way too rich. Very light tan is perfect. White is too lean.
If its smoking black, there's no question that its way too rich. Being that it's an '85 carb, it should have an APT (adjustable part throttle) adjustment. I've never messed with a Q-jet that had that but its probably pretty easy.
The parts from the older carb may or may not interchange and IMO, you should concentrate on making the carb that is on there work.
After that, clean the plugs and drive the truck for a while. Then pull the plugs again. If the porcelain is black or brown, its way too rich. Very light tan is perfect. White is too lean.
If its smoking black, there's no question that its way too rich. Being that it's an '85 carb, it should have an APT (adjustable part throttle) adjustment. I've never messed with a Q-jet that had that but its probably pretty easy.
The parts from the older carb may or may not interchange and IMO, you should concentrate on making the carb that is on there work.
it only leaks there the time i didnt catch it, and it flooded itself out sitting there idling. but yes i need to figure out where its coming from. when its running right theres no smoke. the time i noticed that was coming to a stop at a redlight thats on a hill. the front end was pointing down and it started trying to stall.
so its not flooding now, but. i started out tonite heading north about an hour away, and as usual it started out okay and at the same redlight as usual it started starving for fuel this time, so i pulled over and remembered that i had just hooked up the dual capacity pump valve thing.. (it was unhooked when i bought the truck and ran decent) so i unhooked it and finished my trip,, i know its going to be using more fuel now, but at least i can drive it. i dont know what else i can do to it, tuning wise. should i get a rebuild kit for it?
I think I'd get another core carb (without the goofy pump) to build if that's got the dual capacity pump on it, and it's causing problems.
