Carb Problem

[RedHot71]

  All of a sudden my 1951 Dodge B3J 2 1/2 ton truck will not stay running on it's own.  (Not sure if it is the 251 or 265 cu. in.)  I have to pull the manual choke out 1/2 way & pull the manual throttle out way too far to keep it running.  I rebuilt the carb about 6 months ago & it has been OK since about (2) weeks ago.  Any suggestions greatly appreciated.  Also, any input on where to buy an after market carb to fit this truck?

[1949 Wraith]

Are all your spark plug leads connected correctly? Have you checked your spark plugs? I'm wondering if all plugs are firing.Maybe water in your gas?

[Tooljunkie]

Dirt in carb, or weak fuel pump. Another is a crack in fuel line. 
water as mentioned and depending where gas filter is located that could be plugged as well. 

[minicooper]

Recently, the same happened to my B3C, would die as soon as I took my foot off the gas, had to choke it and leave the throttle open to get it home. Trash (rusty bits from the gas tank) clogged the fuel filter but some got by and got in the carb.. I was lucky and removed the idle screw, blew compressed air though it and it was OK.

 

-Roland

[kencombs]

A big vacuum leak can cause similar symptoms also. 

 

Fuel delivery issues can be tested by removing the pump to carb line and cranking the engine.  Catch the gas in a container to see if it is delivering.  That would help with dirty gas tank, fuel filter or pump concerns.  If that's ok, it could be junk in the carb as others have mentioned.

[Dodgeb4ya]

Vacuum leak caused by faulty brake booster?

[RedHot71]

Thanks for the replies.  It just so happens that the hydro-vac brake booster is has been removed to have rebuilt.  Never even thought it could be the booster w/a vacuum leak.  Will check the fuel delivery & filters as well.  Thanks again!!! 

[Dodgeb4ya]

A 1/2" vacuum line supplies that booster.  Huge vacuum leak if not connected or damaged seal or diaphram. Been there on that issue.

[RedHot71]

Plugged the line for the hydro-vac & she fired right up & idles.  Thanks for the responses.  You guys are a huge help w/these old vehicles.

[Dodgeb4ya]

A note on the Dodge frame mounted brake booster...

Dodge B series used only the "Midland HyPower" single or dual diaphram boosters on 1-1/2 ton and up.trucks with 9-1/2" diaphrams.

Hydro-Vac boosters were a "Bendix" brand booster and were not used in the B series Dodge trucks.

Hydro-Vacs were common on Chevy, GMC, Ford and other trucks.