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View Full Version : Stumped and got a Carby Question



shmoov69
03-11-2007, 06:57 PM
Ok, I got a problem that I cannot figure out. On my 58 Nomad, it has the original 348 with a single 4bbl. It still has the original Carter carby that I rebuilt a couple years ago. It ran fine up until a few months ago. It still runs ok, but it is dripping fuel when I shut it off. The goofy part is that it doesn't start dripping until about 3-5 minutes AFTER I shut it off. Then it drips out the squirter (front only). Which obviously makes it hard to start and also I am sure is not too good on the oil. I have taken the thing apart several times and blown all the passages out and also lowered the float a little bit. It still does it. I cannot feel or hear any fuel in the floats either. It continues to drip even if I hit the pedal a little bit and also if I pop the gas cap.
I am stumped :hmm:
Any help would be greatly appreciated!

Norwoodx55
03-11-2007, 08:23 PM
Well I was going to suggest opening the gas cap, then I saw you already did that. Does the float bowl have any kind of vent? Maybe it is blocked or plugged:dunno:

HILROD
03-12-2007, 07:51 AM
If it still has the WCFB, is it coming out the top vent or the pump arm shaft? Maybe it leaks while it is running but it dries up or you can't see it. The only leaking after it's off part is giving me a headache!:hand: :hammer:

MonzaRacer
03-12-2007, 05:27 PM
sounds like a float issue or the vent is plugged

shmoov69
03-13-2007, 07:47 PM
I don't think the vent is plugged, but I will check that. The thing runs too good to be leaking while it is running IMO. But whoknows! It only leaks out the squirter about 3-5 minutes AFTER I shut it off. Then it drips for about a minute or two.
?
Thanks!

shmoov69
03-17-2007, 04:05 PM
Any other ideas?!??
Thanks

Tech @ BG
03-18-2007, 03:03 PM
If fuel flows once the engine is off, it can be a siphoning situation. Take the carburetor apart, and clean everything out.

shmoov69
03-18-2007, 07:46 PM
Already did it 3 or 4 times! LOL! Any other ideas?

Tech @ BG
03-19-2007, 05:32 AM
Already did it 3 or 4 times! LOL! Any other ideas?

Still sounds like a siphoning issue like you've missed a clog somewhere. Take the carburetor off of the car, fill it with fuel, and place it on top of a coffee can (in a well ventalated area) and see if any fuel drains.

This will at least let you know if it's just a leak, or a vacuum assisted leak (siphon). If it leaks like that you can go back through until you see specifically where it is coming from. If it does not then you'll need to see what exactly is plugged up internally.

crashz28
03-19-2007, 07:15 AM
i agree with tech

Skip Fix
03-19-2007, 10:16 AM
Fuel perculating out the boosters or vents can happen after heat soakign when off. Also if float is set a little high any slosh can drip out the boosters. Weak seat could be allowing residual pressure in line to keep filling bowl or if pump is putting out too much pressure, especially if using a mechanical pump. You can put a pressure gauge in and see if the pump is puttign out good pressure and not leaving too much residual pressure in the line.

You just need to get the tripower I have for a 348 and that will cure it!

shmoov69
03-19-2007, 07:32 PM
You just need to get the tripower I have for a 348 and that will cure it!
Tell me more!!! I have a swap meet tri power for it sitting on the floor, but am not ready to tackle that project yet. Since the carbs are all mismatched and it is a "swap meet" piece! Do you have one that is good for sale?

On the carby issue now, I have had the car on a coffee can and it does not leak out anywhere sitting on the bench. It only leaks after it runs and I shut it off. After it sits several minutes, THEN it starts dripping out the booster. I will check the pressure in the line to see if that is it.
If it is a "vacum assisted leak", how would I go about finding that and fixing it?
thanks again!

Tech @ BG
03-20-2007, 04:22 AM
Well you’re at least isolating where the problem can potentially be. At this point put the carburetor back on the engine, and go through a few checks. Temporarily install a fuel pressure gauge in your line between the pump and carburetor. Now start the engine up (for a minute or two) basically just long enough to get it running, and check you pressure. Now shut it off.

You should be able to determine a couple of things from this.
-If the pressure is correct
-How quickly the pressure is bleeding off, and if your dripping is starting as the pressure is bleeding off
-If continues to leak then you’re most likely looking at a siphoning situation, but if it does not you’ll need to investigate heat soak further.

shmoov69
03-20-2007, 06:37 PM
I'll check it out, thanks!

shmoov69
04-02-2007, 09:13 AM
well, I just drove it back from Dallas to home and it done great. I took it apart one more time before I left and I found that the seat (needle and seat) was not quite tight where it screws in. So, I guess that was letting enough fuel into the passages after I shut it off and causing it to flood out. Thanks for the help!