.75 Corvette 350. Auto runs rough, fuel leaking around accelerator pump, given the age is it best to replace or try to get it rebuilt?

 

Welcome to the forums. I always try to rebuild them before I toss one, If you aree seeing fuel around the accelerator shaft that could mean there is excessive play around the shaft with maybe a high float level because of an old needle on the seat that gets hard after time and gives you a high fuel level in the fuel bowl. Those are common and a easy fix with a rebuild kit. I think Qudrajet Parts .com had a service that you send them your old carburator and they would rebuild it completely. or you can do it yourself its not hard with the parts available. There are several guys on YouTube that can walk you through it step by step for help. I have seen new Qudrajet carburators on Amazon from China that are cheap but get reviews if you want to go that route. I'm using my old 84 GMC pickup Qudrajet non electric carburator on my 77 402 BB now that I think I have got it dialed in. I have gone through it and found some irregularity's that I fixed. It sounds good, good idle and very responsive. I need a very good reason to to toss a Quadrajet carb. I'm looking for mileage not power.

 

Welcome to the forum. I agree with Thomas. I think doing the rebuild on it and getting all the adjustments set up is all you need. I've rebuilt my 73's Quadrajet multiple times over the 50+ years.

 

While I viewed a quadrajet to be a pain in the *** most of my life, they really are very good carbs and fairly simple to work on. Get a good rebuild kit, watch a couple of videos and most important, take your time.

 

High float level can be caused by the foam float absorbing gas and gradually sinking allowing the gas level to rise. If you rebuild, you should replace the float. A brass one is best but a new foam one is fine. When done, you should use alcohol free gas.

Cliff Ruggles has a good book out on rebuilding the Quadrajet.

 

I have heard of floats saturating but I never had one. A high float level is the only way I can see gas coming from the accelerator pump shaft. (small bore not much splashing room) The last Qjet I went through it was an 84 nonelectric 2500 GMC, while doing a through check on the jet passageways that feed the primary venturies using drill bits, I found a big difference in size between each other. It must have come from the factory that way. It's one of those things that don't get checked that often but maybe we should. There was several thousands difference, I normally don't check passages when rebuilding, but I think I will now.

 

It was my understanding a float that is starting to soak up gas would tend to sink lower which would result in a higher fuel level. I did have one that while it was not saturated, it did not set as high as a brand new one did. It hadn't gotten to the point of causing a problem yet but I went ahead and put a new one in.

 

If in doubt replace it , it's cheap. I had seen a few Qjets where someone thought it was a good idea to put nylon tape on the inlet fitting, that works fine for the moment but the next guy comes along and removes the fitting. If all of that tape is not removed it can end up inside the needle valve then the fuel bowl overfills. Bad idea.