carb issues....suggestions

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Backtobasics

Backtobasics

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Carb started misbehaving on the way into work this AM.

Fuel is seeping past the grommet that surrounds the accelerator pump arm, and AFTER shutoff, leaking past out the throttle shafts.

Brand new fuel pump and filter.

I am thinking needle and seat are not sealing? Perhaps float? Float is plasticy thing, so it is not hollow and taking on gas.

I need it to make it over to a buddies tonight, so I can tear it apart. Once it makes it home, it is staying, as I am tire of messing with the fuel system on this car.....

Thoughts?
 
What carb is this.

It sounds like ethier;

A worn out carb in need of a gasket and possible shaft bushing

or

tooo much fuel presure
 
I think the carb is considered a 1945. It is a 3 pce carb, with base plate, main body, and top. It is more "Edelbrock/Thermoquad" type carb (removeable top) then "Holley" (side float bowls)
The carb was rebuilt by me a while back (1 year ago). I ran into some issues 4 months ago, where I changed the jet, and in the process broke the emulsion tube. I swapped the top from another carb, replaced the crusty grommet on accelerator pump rod, and it has been fine, except for the fuel pump, which was replaced last weekend.

Maybe it's time for another carb kit?
 
If you have the phenolic plastic float? Its a good idea to replace them, every rebuild. Or find out the weight their supposed to be and compare. thats the only way to tell if it has become saturated. Thats the deal with thermoquad floats, may be the same with yours? good luck:clock:
 
I saw gas running down the side of the venturi. I think the gasket might have gotten bumped when I switched the top from the old carb over to the existing carb. I have a float, and carb kit waiting at the parts store for this evening.....
 
If you have fuel leaking past the throttle shaft then I'm with you on the float or needle/seat. I had a Holley with a plastic float develop a tiny crack and take on fuel. When it sank it was flood city.

If it's a new pump (especially performance) then Rumblefish could be right on the pressure too.
 
Lunch Update​

Decided to investigate at lunch. Took a few seconds to start, fuel filter was empty.
Started and idled fine. I do see it seeping into venturi between main body and top at idle. When RPM increases, venturi dries up, but seeping comes back at idle.
Idled for 3-4 minutes, shut it off, and fuel squirts out of the air bleeds (then evaporative smoke out of air bleeds, and fuel Drains out of booster, onto throttle blade, and leaks out the shafts and all over intake manifold.

Parts store, replacement type pump, nothing exotic or high performance. At idle, the filter is 3/4 full at best, it never seems to fill completely. Should it be totally full? Should it stay full (or part full) at shutoff? Not sure if there is any kind of check valve etc in the pumps, or if it gravity drains back into the tank?


I have carb kit coming to local O'Reilly store for pickup this evening.
 
I wont worry about what the filter is doing too much. It sounds like you either disturbed the float setting or the float is partially sinking.It's very hard to detect a sinking float unless you want to boil it in a pot on the stove.Hopefully the hloes will open up and the float will siink. But it's just easier to replace them with brass ones. It's something I just automatically do whether the carb needs em or not.
 
I hate this #$%^&*( ing carb.
I rebuilt it last night, with new float. Old float seemed fine, but hey, why not? Old float was foam, new is metal, and tweaked in the box.
Inside carb has some gunk, but nothing too bad. I could not see a spot where the gasket was bad, and all bolts were tight, but rebuilt it anyways. Tweaked float back, and re-assemble.

Started, idled for 5 minutes, no problems. No problems at shut down, nothing. FIXED!

Drive home, stop for a burger, shut it off at the speaker (too loud), and it starts right up.
Shut it down at the window, get food, and it is flooded when I restart. Dies at the end of the parking lot. SAME CRAP. I get home by keeping RPMs at 1-1.5 billion, and it is puking AGAIN. I wonder if float is off, and why it shows after driving 15 minutes on the highway. I hate this with all my soul. I am so tired of messing with it. I have had 2 years of near perfection, and now it is turned to crap. I really wanted to keep it a slant car, but I am really starting to run out of patience.
 
I think it might be solved.
I took it apart again, and the likely culprit was the hollow parts store float.
It was tweaked in the box, and I think once the heat from the engine got to things, it got wedged in the main body, with the needle and seat open.
I also fashioned up a wedge to keep the float from raising up out of the main body. I seem to remember one somewhere along the way, but could not find it anywhere. I dunno if I forgot it last time or I am imagining things.
It started immediately, no leaking. I let it warm up, adjusted the air fuel mixture, and idle.
I am not going to jynx myself, and claim victory, but merely say, it seems to be working for now.
 
Frustration has led me to walk away from many a carb issue. Lets hope it's all good this time!
 
needsaresto said:
Frustration has led me to walk away from many a carb issue. Lets hope it's all good this time!
Click to expand...

Agreed.

Life is so much easier when I can drive my Mopar. My daily driver ram has been down, forced to drive a Ranger. It's quiet, automatic, and slow. I am bored off my rocker. I need a manual, I need something that makes noise. Hopefully the Dart hangs together while I get the Ram fixed, then it gets body work and paint.
 
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