steve4570

My fuel drains away from my Quadrajet and needs to have the engine cranked over to pump fuel to the carb. The clear plastic inline fuel filter has no fuel left in it when left for a day or two. Car is a 1970 454. What would cause this? Steve.

7t9l82

some how it siphons back thru the fuel pump. the quadrajet has a small fuel bowl and gets sucked back out because of the way it is built. i have a quick fuel 750 and no longer have the problem, or any other related to the quadra jet. let the attacks begin. happy thanksgiving

doorgunner

I have the same problem. On military aircraft we installed a one-way check-valve in any fluid line that would siphon dry.

I think I'll try that on my fuel pump pressure side---that way the bowl won't lose the fuel---and if it does there will be enough between the pump and the carb to re-fill it immediately.

But I wouldn't be surprised if a knowledgeable member knows just what we need to replace on the quadrajet to prevent the bowl from emptying!

gjohnson

Do you have the filter that's inside the carb? I believe its spring loaded and when the engines off it closes up the line to prevent draining back out.Works like a check valve

steve4570

No I took the filter out but I will put it back in. It does have a spring that pushes against the filter. Thanks gjohnson. All the best, Steve.

1Fordman

The well plugs in the carb float bowl were notorious for leaking. The old time cure was to epoxy the plugs to cure the leaks. Haven't been into a
Q-Jet in years so there may be a better fix than the epoxy.

7t9l82

i do not miss this

doorgunner

I'll try all your advice since I haven't been inside a q-jet in 45 years!

(So THAT'S WHAT the little rubber "stopper" is for in that tiny fuel filter inside the car inlet?!?!?!)

The $3 repair gets done first.....if that doesn't cure the problem---then a $5 check-valve goes in!

(Last resort----a Holley 600---it cured all the problems on my '36 Pickup SBC)


Thanks Steve4570 for letting me in the conversation) and thanks Men for the info!!!!!

Danish Shark

http://quadrajetparts.com/rochester-...lug-p-122.html

lvmyvt76

don't get rid of your carb, they were a great carb when properly adjusted and taken care of, ask Lairs or get his papers on the Q-jet carb!!!!

Mike Ward

Get rid of the fire hazard bubba filter and do this:

Shark Racer

I have a friend doing burnouts in his 1980 305 Corvette after I rebuilt his stock electronic QJet. I think they're decent carbs.

7T1vette

Most of the little corrugated paper filters that fit into the carb's fuel inlet have a [black] rubber check valve at the inlet hole of the filter. The spring only holds the filter in place so that the fuel can't bypass the filter. If the filter doesn't have the little black check valve, it won't help the 'back-flow' problem.

Also, make sure you buy the correct filter for that inlet housing. There are several sizes. And, if your carb originally came with just the sintered bronze filter, I don't believe there are any corrugated pieces that are small enough to fit [properly] in that carb.

Good luck. As a last resort, you could always buy an in-line check valve to stop the back-flow issue.

tmacd

I am having the same problem with my 77. I have been told that I have an edelbrock carb with a plastic filter at the front next to the cylinder cover. Will the check valve cause the car to start better? When you guys say "bubba filter" what should I replace it with? Also are edelbrock carbs any good at all? Thanks

gcusmano74

Four possibilities.
1)Install the fuel filter with the correct check valve.
2)Take the float needle valve retainer clip off so that it requires fuel
pump pressure to lift it.
3)Install a fuel inlet valve in the float bowl that has solid sides. Many of the available inlet valve bodies have slotted sides and can allow drainback of most of the fuel out of the bowl.
4)Fuel is evaporating due to heat soak after shutdown. The only thing that MIGHT help is to install a heat shield under the carb.
Good luck.

tmacd

Thanks for the info, #1 option looks like the only one I could address with my present expertise. Would I have to order one of these or would local auto parts have such a thing?

Mike Ward

Best start your own thread instead of hijacking this one.

tmacd

OOOPS....seems kind of rude, thought we were all in this together eh , my mistake I'll be more careful next time

pacecar620

Yes he is. ignore him. He irritates everyone. 10 year member and he thinks he owns the forum. Oops, shoulda started my own thread, eh?

Mike Ward

Yes, I'm Mr. Nasty.

Not hijacking is more about getting people to help with your individual specific (Edelbrock) problem and not be confused with a not really all that similar (Qjet) problem.

Your choice.