yes, a new problem. i rebuilt the carb because i thought that, since it had sat for so long, it's a foregone conclusion that it would be a good idea. i bought the kit and proceeded. the surprising thing is that it looked as if it was rebuilt last year. clean as could be. absolutely no varnish or wear of any kind. i finished the rebuild and installed the carb. i did not take care to replicate the choke settings (manual choke) regarding fast idle. at any rate, it starts without a problem but it will not run without the choke engaged. when i open the top plate, is stumbles and dies. it run fairly smooth when choked, but i obviously cannot run it that way.
does anyone have any suggestions as to what may be the problem?
i'm almost tempted to tear it down again and start over.

 

Did you reset the idle mixture screw?

 

i did. and, they were in great condition.

 

They may be screwed in too far, limiting fuel flow. Adjust them once it's at full operating temp using the "lean best idle" method described in the Weber instructions. That will make sure the mixture is set for the most steady idle over the widest range of temperature and elevation changes.

 

What engine? 240-300 I6, 352? What model carburetor?

 

Did you mess with float level anyway it starving for fuel

 

I would check the float. It was drilled into me at a young age to never tip or flip the carb. If the float is not sitting on the pivot correctly, it will give you trouble. I would also check the rubber fuel lines for age or kinks. Just my two cents.

 

Yes it helps if we know what carb you / we are working on.
You also did not say how far closed the choke has to be to get it to run?

As a start have you checked that all the vacuum hoses are in place and for vacuum leak(s)?
Dave ----

 

i apologize. i got ahead of myself.....352 with the stock 2 bbl carb. i believe its an autolite carb?
i only adjusted the float to match the specs in the rebuild kit. going from memory it's 27/64" or something like that. i will definitely revisit that measurement. i'll take the carb off and adjust it on a bench. i really hate doing it on the motor.
as far as the throttle plate goes, it runs perfectly at 1/4" to 3/8" gap at the top. if i open it another 1/4", it will stumble hard and start to die. full open and it's over with.
as far as fuel lines being suspect, they are all new rubber fuel line. there is very little stock metal fuel line left in place. and, what was there is in excellent condition. as i said, this truck was very well taken care of and it was stored without a drop of fuel in the tank or carb.
vacuum hoses. i'll double check them. the only ones seem to be the large hose coming out of the rear base of the carb and the other is a hard line going to the vacuum advance canister, i believe.

 

Choke on a lot or just a little?
It can tell us how much of a vacuum leak you may have.
Dave ----

 

the choke is on almost full. maybe 1/4" gap at the top of the throttle plate. it runs great if i leave it like that.
i sprayed the base of the carb with carb cleaner to see if it was leaking around the base gasket. no dice. no leaks.
it does have an exhaust leak at the connection between the manifold and the exhaust pipe....essentially the first joint after leaving the motor.

 

Being closed that much I would say is a pretty big vacuum leak.
All hoses in place?
Try blocking off power brake hose & PCV hose to see if they do anything.
Any other vacuum hoses on the motor?

If nothing changes pinching off hoses I think you will need to pull the carb apart to recheck that the right gaskets were used as that is the last thing you played with when this started.

BTW I did have a Holley carb that came on a car that had a vacuum leak that I tracked down to being inside the carb.
I dont know if it was wrong gaskets or not as when I rebuilt it I matched up the gaskets so if wrong I put wrong back on.
My fix was replace the carb.
Dave ----

 

i'm on it. no power brakes on this beast. but i will pull off any other vacuum hose and report back. i'm definitely going to pull the carb off of the motor and give it another set of looks to see if anything is amiss. thank you....great advice on the second look.

 

well, i found the issue (i believe). #10 in this exploded view of the carb seems to have been slightly cocked in it's position and not seated fully. i took the carb off and took it apart to see if i could find ANYTHING amiss. put it back together, installed it, started it as usual full choke). it started right up and idles perfectly. i pushed the choke in and it still runs beautifully. i'm so psyched. it has a tiny stumble, so i'll give it new points and plugs.

 

Good to hear you found something amiss.
Once you had the motor up to temp did you adjust the idle mixture screws?
Dave ----