Hello.
I am a newbee to this forum.
Of course a newbee with a vehicle problem.
Pretty original, huh...
I would rather be a newbee with answers for all.
Anyway,
My van is an e-100 w/302 from late 1973. Th last of the flat nose econolines before they added the extended hood.
The van is stalling when driving comes to a stop. when comming to a stop, it studders and stalls. Idle w/ tranny in drive while sitting still is good. Drives ok but there is some clacking(Could be ping, Im not sure). If I drive down the road and step on the brakes for a traffic light or stop sign, it shakes to a stall immediately. It starts right back up again. Shakes then stalls next time I come to a stop, not while driving.
I'm missing something somewhere, but what?
I have checked everything I could think of and I have come to find no possitive diagnosis.
I did notice the vacuum pressure is low, but I have not found any vacuum leaks.
I've sprayed around gasket seals but didn't find anything. For some reason, I have lost some power, and this stalling problem.
The stock carb has no air mix screw adjustments in front of carb??!!
The carb float seems too high also. Some of the stock motocraft carbs were a royal pain to deal with back then from what I understand...
Anyway, Tried timing adjustment, It either clacks when slightly advanced, or shakes and stalls as you retard the timing. Has good oil pressure.
I am lost now!!!
Please help if you can.
Thanx,
jsx

 

check your spark advance, it has a vacum diaphram and it does go bad. that will cause the vacum to be low, and the timing to be retarded.

the carb should have adjustment screws on the front, unless it is a holley. holley's have them on the sides of the metering block between the bowl and the venturies.

also check the throttle shaft play. check it at idle position, half throttle position, and full throttle position. make sure there is no play in the shaft, that is a major airleak that will cause all sorts of weird problems.

 

Thank you I'll check these pointers.
As far as adjustments on carb, I'm still finding none. I think this motocraft may be an Autolite. I had a friend tell me to find these adjustment screws and looked for them with me. Conclusion on this was that this carb had no screw adjustments.
js

 

Check your vaccuum line all the way from the carb to the brake booster for cracks or deterioration. make sure the check valve on it fits TIGHTLY in the rubber grommet on the booster; I had trouble with this many years ago in a 73 merc I had.