Hi guys. I am having one hell of a time with my carb on my 78 Bel Air. I had to get towed because all of a sudden when driving, my carb floods, like I mean really floods.I have replaced the fuel tank, sending unit and fuel pump due to rust contamination and after the flooding started I have since installed a carb kit, cleaned the carb really good, removed lots of gunk and rust sediment and I am having the same problems. Could a pump go bad and provide to much pressure, because it shure seems like it, as soon as it starts, its like the pressure just jumps up as soon as its at engine idle speed causing really bad flooding, I need serious help guys!
rabbit64cs said
Mar 7, 2010
is it possible that the gasket under the seat ( of the needle and seat ) got missed on reinstall??
pull your fuel line off and connect a test gauge, should be around 3 - 4 psi out of a stock pump. It is possible that something is stuck in the pump, not sure if they have an internal bypass to limit output pressure??
a gauge will be your first line of trouble shooting !!
72 luxo said
Mar 7, 2010
Thanks. I am almost positive that the float system is working in the carb, new needle and seat and yes that gasket was installed under the new seat, those black plastic like floats dont ever go bad do they?
rabbit64cs said
Mar 7, 2010
they do,, but in light of your recent rust issues,, check your fuel pressure first.
72 luxo said
Mar 7, 2010
Yeah, I will have to make a temporary fuel line with a T fitting to hook a guage to, because it has the factory style hard line.
mike67sd said
Mar 7, 2010
What carb are you running?
Did you rebuild ?
If its a Qjet, I'd check the float levels and make sure there was no crap caught in that valve.
If its a Holley you may have a bad float in the secondary bowl.
And remember its never a bad idea to run two fuel filters ....
I run a fuel pressure guage on my Holley and it runs 6-9 psi off my stock pump.
rabbit64cs said
Mar 7, 2010
no need to tee the line , just remove it from the carb, and push on some rubber hose with a clamp , there will be enough fuel in the carb to run for 30 sec. or so.
73SC said
Mar 7, 2010
Get a big screwdriver and give the body a few good raps. If the float is stuck it won't be aftet that.
dualquadpete said
Mar 8, 2010
I'd go with pressure reading as well. Ran into this on a 57 C hevy, guy put new pump on & then carb. started "flooding" He was at the carb many times, before it was suggested to check pressure, he kept saying "it's a NEW pump" turned out it was putting out 12lb. & blowing needle & seat open. Just because it's NEW doesn't mean it's going to work!!!!
72 luxo said
Mar 8, 2010
If I check the pressure with a guage on the end of the line wont it blow it off the line because the fuel has nowhere to go? I am running a rochester monojet on a chev 250 inline six and yes I have just installed a new pump, could a new pump fail and kick out to much presure? ALL THE HELP I CAN GET WOULD BE GREAT, as I am getting quite frusterated, thanks everyone.
rabbit64cs said
Mar 8, 2010
No worries about blowing the gauge off, it's the same situation as when the needle closes in the carb. Hose clamp it to be safe. The fuel pump is supposed to bypass at a certain back pressure, and not build pressure.