My friend has a 73 F-100, FE block (360) w/ a Motorcraft 2150 2bbl. It wasn't running right; missing, etc. On cold start-up, so I cleaned and re-gapped the plugs, two of which were fouled, checked plug wire resistance, set the idle air mixture, and properly gapped the points. The choke was set correctly, so when I mashed the accelerator to set the choke, it fired right up when I bumped the starter. However, when you tip into the throttle, it starts loading up, missing and backfiring. Does this sound like a problem with carburetion?
You need to set the choke pulloff for the correct angle so the motor can breather correctly.
December, 9, 2012 AT 5:42 PM
It is acting as if the choke is engaged, however the choke is set correctly- it pulls completely open within about 5 min, and the problem is only occurring when the choke butterfly is wide open. Could this problem occur if the accelerator pump diaphragm is ruptured and leaking?
December, 9, 2012 AT 5:49 PM
Power valve may be the issue if it happens hot.
December, 9, 2012 AT 8:12 PM
Duh! Thank you, Roy! I don't know why I didn't think about that. I used to turn wrenches for Ford back in the early '90's (back in the EEC-IV days) but I haven't had the pleasure of wrenching on an early '70's Ford in years. Just goes to show if you don't use it you lose it. Thank you again- I replaced the power valve and it runs perfectly now. I appreciate your help!