foulpalamont

Hey all-I'm in the process of fixing up my 1964 Oldsmobile Jetstar 1. After having sat for 25 years, I just recently got it on the road and am very excited. Excited, that is, until every time I take it out, it seems to flood on me. When I pull the air filter housing off, the carb is dripping fuel off the exterior. I had it rebuilt by a shop that I do trust, and I just today had them dial it in for me but after I had it out for about a five mile scoot, I pulled into a gas station and it stalled out on me. The only thing that barely got it going again was stomping the gas to the floor and holding it there while I turned the key. The only thing that kept it going was turning up the idle to keep it going. I have also rebuilt the fuel pump and replaced all of the lines from the gas tank to the carb. What should I be looking for to get her to run more lean? I noted the "Choke Thermostat" on the side had a "Rich" and a "lean" marking on it and that seems enticing, but I really don't know what that does. Is that only for startups? Also, when replacing the lines from the gas tank to the front, I noticed that the return line was capped with a screw and left loose in the engine bay. Could it be possible that it's not able to return the unspent fuel? What would they have blocked this off in the first place? Thanks in advance,
Brian

foulpalamont

Here's one theory, I just had. When I got the Jetstar, I was told that one of the major problems with it was the carburetor. The shop that rebuilt it did say that it was kind of a mess, but they're reputable. The fuel filter housing has been plugged and the fuel return line has a plug in it as well (pictures attached). Would it be feasible that the way the shop "fixed" a messed up carb that wasn't getting enough fuel, was to plug the return to force more fuel into the bowl? And now that it's been rebuilt, the return line being blocked is causing it to flood?

oldcutlass

First off is there a fuel filter somewhere in the line? The lean rich setting applies only to start and warmup, once the choke opens fully its NA. Check your fuel pressure make sure its not too high. The return line is there to prevent vapor lock, usually on A/C equipped cars, the engine will run without it. Most often your problem description is caused by the float being too high. Can you take your car over to the guy who rebuilt the carb for diagnosis?

foulpalamont

Thanks for this. There is a filter in the glass bowl attached to the fuel pump and there's a screen filter that is at the very end of the fuel line that goes into the carb. When i was installing it, the filter looked clean and shiny but should I be checking those things? I wonder why a clog would cause a flooded carb. Wouldn't that cause too little fuel getting to where it needed to be? Also, when the carb was rebuilt, there was no float in the rebuild kit. Do these carbs have a more permanent one?

oldcutlass

If there was contamination in the fuel system a piece of crap can get wedged into the needle and seat. If the float is set too high the carb will flood. If there is not a real paper gasket fiilter in the bowl, the little screen will not stop some crap from getting through. Floats are purchased separately from the kit. If you open the carb, your warranty becomes NA. Talk to the guy who rebuilt it.

joe_padavano

FYI, the title of this thread says "Quadrajet" but a 1964 Olds will have a 4GC, not a Qjet. People sometimes get confused because the 4GC has the logo "Quad Jet" on it. Not the same thing as a Quadrajet, and nothing in common.

shiftbyear

Another thing to look at is fuel pressure, just because the pump was rebuilt doesn't mean the pressure is correct. Many old carbs specify the desired fuel pressure in the factory manuals. Sometimes 5psi is the max on an older carb. It is very bad for the motor to be injesting large amounts of raw fuel. Check oil level to make sure large amount of fuel haven't bypassed the rings. Good luck

Macadoo

Sounds like a stuck float to me. I realize it's a fresh rebuild but it could still be stuck. Try rapping on the top of the carb (not too hard) to see if it releases. Or maybe the shop used the wrong float setting spec. Easy to do. Maybe open it up. Carbs aren't as scary to work on as one would think.
Just a thought.