Carb issue??

Hello all,

I'm a recently new member to this forum. I'm having trouble with my '41 Linc Cont and thought I would poll the experts.

I recently decided to get our lincoln running after it had sat for 6 or so years, before then it probably sat for 7 or so years. Everything is "working", but i do have a leaking rear main seal. Other than that, everything is surprisingly functioning as it should with one exception. I rebuilt the carb, and adjusted the idle screws with a vacuum gauge. I believe it was somewhere around 18" at idle on the gauge (measuring manifold vacuum). Everthing runs smooth under no load. Acceleration is good through all three gears. When i start cruising at a constant speed, the carb seems to become flooded. I start loosing power, the car never shuts down though. It's almost as if i loose several cylinders. If i clutch and rev the engine a few times and let it idle for a second, it will act as if nothing happen and can handle a constant load for a little longer. Then it starts the same thing over. It will backfire if i don't cycle the carb with fuel and let idle for a few seconds.

What could this be? Do i have my float adjustment off? I've pulled this carb apart more times than I can count. I've checked the main jets, and they are #54 with a 7.5" power valve (correct for the carb). I've also checked to see if my power valve is faulty by checking for condensate (suggested in previous posts). I can't see that i have anything else wrong. I haven't specifically checked for a vacuum leak, but i think i would see a vacuum leak at idle before a constant load. Any thoughts?

Hello all' date='

What could this be? Do i have my float adjustment off? I've pulled this carb apart more times than I can count. I've checked the main jets, and they are #54 with a 7.5" power valve (correct for the carb). I've also checked to see if my power valve is faulty by checking for condensate (suggested in previous posts). I can't see that i have anything else wrong. I haven't specifically checked for a vacuum leak, but i think i would see a vacuum leak at idle before a constant load. Any thoughts?[/quote']

Have you checked the fuel pressure?

No I haven't. What's the best way to check that? What's a good pressure? Thanks.

If you are using the standard Ford fuel pump it will produce 1-1/2 to 3-1/2 psi but I would check the float level and the float valve itself. If you hold the air horn upside down the float will complete close and not leak with just the weight of the float. Re check the snugness/ seal at the nozzle bars...any looseness caused by a mismatch in height between the nozzle bars and the accelerator spray nozzle. Loosen the back clamp for the nozzle bars to check for looseness at the front (near the fuel bowl). Normal fuel level in the bowl is right at the level where the nozzle bars seal at the carb body. I would recheck the power valve for leaks just to be sure. Some times the brass check valve for the accerator circuit (under the spray nozzle) is missing and this might cause some over richness. If the carb is operating like it's supposed to the idle mixture screws should be 1/2 to 3/4 turn out ( from seated).

Ok. I'll take it back apart and look at it. It does seem that the car has been running rich on idle, and I don't remember seeing that check valve there. Thanks, I'll let you guys know what I find out.

Found the issue. It was leaking at the nozzle bars. I replaced the 5 round gasket seals and it's running good now. Everything else was ok. Thanks for help.