Fuel problem on my '40

New carb is being delivered today and we’ll find out if that’s the fix. If not….the pump is the last item to change and I’ve got a new one ready to go. More later !

Thx
 
Mike
My question was "AFTER" it sits for the magic "20 minute" period, NOT right after you start it and it runs fine and you shut it off. IF your plugs are both sooted over AND "WET WITH FUEL" after 20 minutes of sitting "AFTER" it ran good, I'd be looking to see "WHY" they are all wet when it hasn't been running for 20 minutes!!!! Just to clarify
 
Hope it works for you!!!! Fingers crossed!!!


Mike, just another thought....my frame of reference (so to speak) comes from our 32 and the Detroit Lubricator carb we had on it. It would perform and run the car beautifully BUT every time after and car sat for a week or three, the float was stuck and when you would go and start the car.....I would have to open the hood and stand and watch it because fuel would start pouring out of the carb. You could take a wrench or handle of a screwdriver and tap on the top of the bowl cover and that would free the float back up and everything worked as it should!!!! BUT that "stuck" float was the issue!!! OR before we would start the car we would tap the cover of the bowl to avert the above scenario.
 
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Rock……..new carb showed up from UPS late last night so I’ll be installing around 5am this morning. Will advise once I fire it up. I tried tapping on the float area also but no luck. I’ve also got the new Airtex Electric Pump ready to install in case I still have probs. There’s not much else to change !!

Thx……Mike
 
et al.....Installed the new Dennis Carpenter Carb early this morning.....and other than forgetting to hook up the fuel line from the fuel regulator ...which won't get into....she fired right up and ran perfect for 15 minutes at 500 rpm. Just went back after hour and a half and hit the button and fired right up and purred like a kitten again. NO smell of fuel at all ! Took it for a short ride and put back in the barn and will try again in an hour or so, but the drama appears over. The Reg shows 2.8 psi and I'm going to take that to 2.5 psi today. It's amazing what $ 500 bucks will do huh ? But hey....I want to drive my car and at this point I could care less.

Just want to thank all for comments and suggestions during this ordeal. Much appreciated.

Thx...Mike
 
I'm still betting it was a cracked, porous, or ill-fitting carb body. When and if you get enough time, it might be instructive to disassemble your old carb and give it a thorough inspection and see what you find.
 
It would be interesting to find out how much fuel pressure it really takes to "overpower" a needle and seat on your carb. I ask this because if your fuel pump has a max output of 3 psi, why would you need a regulator at all?

I know that on my Holley 4 barrel it's about 7 psi. The fewer components you have in your fuel line eliminates potential component failure and aggravation.
 
Rock....plugs are getting clean, but there was no wetness when I pulled a couple plugs before the new carb.

Super and Tub.....I plan on keeping the old carb and doing as suggested to check it all out. I did hold the float under water once to check for bubbles and there was none.

Just got back from a 10 mile run. It stumbled a bit 3 or 4 times going up some hills, but other than that it was smooth as glass !

Thx.....Mike
 
Fordy..... I put on the reg from a suggestion here on the Barn. For 9 years I had NO probs until 3 weeks ago ! I've it set for 2.5 psi right now and seems to run fine. I was told 4 psi may be too much, so that's why I reduced it.

Right now my car is drivable and I plan on enjoying it !

Thx....Mike
 
Mike: When you get time it's interesting to read about and visually see how fuel pressure affects flow based on demand.
https://www.offshoreonly.com/forums/general-q/346573-fuel-pressure-carbs-volume-vs-psi.html

Peruse these links.
https://www.google.com/search?q=how...7j33i299l2.13400j0j4&sourceid=chrome&ie=UTF-8

https://www.youtube.com/watch?v=nAe_5YwWoV0

Also, since you now have your old carb to play with, go thru it piece by piece so as to fully check it out and practice rebuilding it yourself. I bet you will be successful unless the casting is porous as has been mentioned earlier.
 
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Fordy …….. I plan on doing that check all the pieces to see if I can spot anything. I’ll follow up at another time.

Rock ……pulled two more plugs on the left bank and running much cleaner ! Thx for the tip.

I just took a run around our lake which is 18 miles. Perfect and didn’t stumble at all this time.

When I got home I pulled the plugs and was wiping everything down and checking for leaks. None at all, but I did find that the larger upside down screw that holds the float bowl to the carb base was never tightened !! Was able to use my angle screwdriver and tighten that little bugger up !!

Have a good weekend guys. I am…….!

Thx……Mike
 
I think finding that leaking screw will void the porous casting possibility.

Now, patiently rebuild your old carb like the pros do.
 
19Fordy said:
I think finding that leaking screw will void the porous casting possibility.

Now, patiently rebuild your old carb like the pros do.
Click to expand...

The way I read his post is that the loose screw was on the new carb, not the "leaker". Why else would he have to use his "angle screwdriver" to tighten it?
 
Tub ……yes on the new carb and not on the old one.

Took another run around the lake and all is well. It’s great having my car back. Washed and polished it today. Smoked a cigar and had a couple Jack Daniels. Life is gooooood ! LOL

Mike
 
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