Quadrajet rebuild necessary???

[wonl2]

I have a 1979 Corvette L48 with a 350 engine. The spark plugs are "sooty" and black carbon shoots out the tail pipes at initial start up. I know this is caused by the fuel mixture being too rich. I calculated that the car only gets 8 mpg with "very conservative driving". I don't do quick starts or race around. Recently the engine is hard to start when it's cold outside and engine seems to be flooded. Only 60K miles. Thinking the carb needs to be rebuilt. Any suggestions on the possible problem? Suggestions for rebuild kits if necessary?

Thanks in advanve for all feedback

Phil

 

[tmkassin]

This sounds like the float bowls are overflowing. You need to at least replace the needle and seat. If it has brass floats make sure to check them to see if they have gas inside them. Most kits back in the day didn't include floats. It's been many years since I rebuilt one but most auto parts stores can get the kit.

 

[Vettehead Mikey]

Make sure the choke is operating properly.

 

[Tom Bryant]

Yes. There is a vacuum diaphragm that pulls the choke off on the front corner of the carb. Pull the rubber hose off then push in the rod. Cover the hose with your finger and release the rod. If it stays in it's good. If not it needs replaced. Also if your carb has a fiber float it my be absorbing fuel and sinking. Very common.

Tom