I recently bought a 69 coupe project with a 350 and a quadrajet. When I first got it on the road, it wouldn't get enough fuel. It would run well when driven slow, but when you hit the throttle, it would start bucking. I changed the fuel filters (inline and one in the carb) and it made a huge difference. That was the first tank of fuel. After I refueled the second time, it drove great for the 2 mile trip back home. A couple days later, I took it out for a drive and as I started to go, it seemed to start sputtering. I was able to get it back home without too much difficulty. So I decided to replace the filter once more thinking that crap in the fuel tank was stirred up when I refueled and clogged it up. Took it out again a week later and it ran good at first, but then after it warmed up, it wouldn't idle and died. I opened the hood and there was fuel on the intake and the engine was flooded. It wasn't leaking out of the fuel line, or filter location. I was able to get it started again and made it home, but it still wouldn't idle. I pulled the air cleaner and noticed fuel was pooling inside the intake. I'm figuring it has something to do with the float valve in the carb. The more I type, the more I'm convinced the float valve isn't closing. Any thoughts?

 

Sounds like you've picked up some trash from the tank & its clogged the needle valve.

First thing to do is take your carb off, turn it upside down & shake it a little & you might get lucky (the next 100 posts will say to never do that because you might have to take it apart)

If that doesn't work, the next thing to try is... "take it apart" & clean it & you're out nothing but 20 minutes by trying option 1 & a few bucks for new seals. Unless, you have OCD & cant stop yourself from thinking that while its apart it would be a good time to just go ahead & rebuild it, spend vast amounts of time & money meticulously rebuilding it yourself for no apparent reason what-so-ever & realize in the end that it has been rendered FUBARed.

In that case, fear not you can always get on ebaY & get a stock used RQ for next to nothing, a rebuilt RQ for a little more or better yet an upgraded RQ for less than 1/2 of retail of a new one. (850 cfm for about $300)

Not saying you should follow this path exactly but in heine sight I would rather have just skipped a lot of the middle part myself.

 

I haven't heard of turning it upside down and shanking it. I think I'll just pluck it off the manifold and start diggin into it. Thanks. By the way MrGoFaster, nice paint job!

 

Another thing you can try is block of the fuel line then start the car run until it emptys the fuel bowl, reconnect the fuel line and re start the engine. What this does is let the needle off the seat, and as fresh fuel runs into the bowl it hopefuly flushes out any debris that might be fouling the needle. If this fails you should pull the carby off and clean it out.

 

Here's another suggestion. These Q-jets have foam floats that sometimes sink because they are a cheap replacement or just old. I've replaced them several times to solve a similar problem. Go buy a top quality float from a reputable source like a NAPA auto parts dealer or Government Motors, ACDelco. The Q-jets are great once you have them sorted out.

 

I have it figured out! After another flooding episode, I rebuilt the carb. The float valve spring clip was not connected to the float properly. Problem solved!