Carb Swap = headache HELP

[wild70stang]

Well I had a nice four barrel (carter afb competition series) and something screwed up so now im borrowing my brothers 2 barrel of his old truck (we rebuilt the carb before installing it). The carb is mounted and the engine runs, except for a few problems. Problem one is that when braking, at about 20 mph the car starts to die and at about 5-10 mph the car struggles to turn over for about 2 seconds and finally resumes as normal. The other problem is that when shutting up the engine TURNS BACKWARDS. With the hood up I litterally see the fan go the other frigun way. My brother who is this pain in the ass army mechanic has been helping me out. The engine idles fine. We removed the wire to the electric choke since the choke plate was causing the car to die when shifting into gear. The car was surging really bad and he was playing around with the timing and the idle adjustment till the car idled fine.

ALSO if anyone thinks its the vaccum on the brake booster its not. I drove 5 hours (anahiem-Fresno) and had no issues with vaccum leak. The problems only arised after installing this carb.

 

[enferno]

did you rebuild the one you're borrowing at all?

could be a whole mess of problems.

you went from a 4 barrel to a 2 barrel . . could be a vacuum leak from the intake swap too . .

 

[wild70stang]

I guess I was editing my earlier comment while u were typing. My brother rebuilt the carb since he and I dont see eye to eye and it was his carb so I stayed away from it. He had a carb spacer that was designed to fit a 2 barrel carb to a 4 barrel manifold, wierd. But no vaccum leak that we have found yet.

 

[enferno]

that might be your problem putting a 2bbl carb with one of those spacers.


what cfm is the 2bbl at? it might be too small for your 302.

and how did you check for vacuum leak? spraying carb cleaner around all the seams?

 

[wild70stang]

My brothers carb came off of his 60 Ford F-100 and he had a 302, then he changed to a 351 and it still ran fine till the tranny crapped out. I will spray some carb cleaner or maybe a soap/water solution around the spacer tomorrow to check the vaccum.

 

[rbohm]

you do realize that you have to set the idle speed in drive with the vacuum advance disconnected and plugged dont you?

 

[D.Hearne]

that might be your problem putting a 2bbl carb with one of those spacers.


what cfm is the 2bbl at? it might be too small for your 302.

and how did you check for vacuum leak? spraying carb cleaner around all the seams?

Funny then the guys running these in Circle track cars have no issues with a 2 bbl on a 4 bbl intake No such thing as a too small carb either. Smaller they are the better they run on the street.

 

[D.Hearne]

Well I had a nice four barrel (carter afb competition series) and something screwed up so now im borrowing my brothers 2 barrel of his old truck (we rebuilt the carb before installing it). The carb is mounted and the engine runs, except for a few problems. Problem one is that when braking, at about 20 mph the car starts to die and at about 5-10 mph the car struggles to turn over for about 2 seconds and finally resumes as normal. The other problem is that when shutting up the engine TURNS BACKWARDS. With the hood up I litterally see the fan go the other frigun way. My brother who is this pain in the ass army mechanic has been helping me out. The engine idles fine. We removed the wire to the electric choke since the choke plate was causing the car to die when shifting into gear. The car was surging really bad and he was playing around with the timing and the idle adjustment till the car idled fine.

ALSO if anyone thinks its the vaccum on the brake booster its not. I drove 5 hours (anahiem-Fresno) and had no issues with vaccum leak. The problems only arised after installing this carb.

Autolite 2100? The float's not adjusted correctly causing the stall when you brake too quickly.(too much fuel in the bowl and it's sloshing out the vent tubes into the throttle bores, flooding the motor) Engine's not running backwards, it's dieseling, or running without the ignition on. Throttle blades are open too far, letting fuel/air into the intake after you shut it off. Start over and tune it till the motor will idle with the throttle blades only opened slightly, you'll need to bump the timing to 10-12* BTDC and adjust the mixture screws farther in.

 

[wild70stang]

Thanks for the hep guys. I tried to tell my brother how to set the idle but its like talking to a brick wall since he thinks he knows everything cause "hes a mechanic in the army."

 

[wild70stang]

ok the electric choke is crap and needs to be replaced. The carb is a motorcraft 2100. I now need help adjusting the float. We tried to follow the instructions on the rebuilt kit but my brother couldnt figure out where or how to bend the tang. If someone has a picture or something detailed so we dont screw it up.

THanks!

 

[10secgoal]

Autolite 2100? The float's not adjusted correctly causing the stall when you brake too quickly.(too much fuel in the bowl and it's sloshing out the vent tubes into the throttle bores, flooding the motor) Engine's not running backwards, it's dieseling, or running without the ignition on. Throttle blades are open too far, letting fuel/air into the intake after you shut it off.

Exactly was I was thinking.

I tried to tell my brother how to set the idle but its like talking to a brick wall since he thinks he knows everything cause "hes a mechanic in the army."

Ask him if the Army taught him to actually work on carbs. Or if he pulls the parts off, installs new on and send the old one to a contractor to be fixed.