LovinStangs97

I have a 4barrel carb on my car right now. I'm having problems with it starting and it's in really bad shape from the person I bought it from not knowing how to work on a car the right way instead he just did everything the easy short cheap way just to get by. So my question is if I go from a 4barrel carb to a 2barrel carb will it make much of a difference in anything? Fuel efficiency or being easier to start or anything? I just need to get rid of the one I have now. It's killing me. My idle at first was set really high and I dropped it down a little bit but now it's too low. What is the ideal or best idle that I should set it out for it to not want to stall out at stop lights? Thanks so much

GreyStang

Easier to either replace the 4barrel with another 4barrel or have the one you have rebuilt. Swapping a 2barrel means you'd have to replace the intake manifold too.. And after all that swapping your fuel economy might only go up a little bit

Colorado_Mustang

A 4v carb will usually get better mileage, as long as the secondaries aren't being used that is. The primary side of a 4v will flow less than a 2v, and use less fuel. It will also deliver better throttle response for the same reason.

Which carb do you have? A rebuild kit is generally the best way to freshen a carb. If the baseplate is worn, a new 4v carb will be cheaper than a 2v replacement with the adapters needed to fit your manifold.

67mustang302

+1 on 4bbl better mileage/response when set properly. As far as your problem it's either a tuning issue or the carb just needs a rebuild. It may not hurt to rebuild it regardless since you should be skeptical of what the previous owner may have done to it. Which carb is it? Autolite, Holley, which model etc?

LovinStangs97

I'm not sure...I know is a Holley but I will look tomorrow and let you know.

Gary H

Have you ever worked on a carb before? They're pretty easy once you know how. Look for the model number and post it. It should be on the front of the air horn.