Hopefully someone can shed some light on this problem. I have a 72 with the original F motor (~200K) and DUI dist. Carb was rebuilt 2 years ago by Jim C, new OEM fuel pump within the last year, and the rig has been running fine until a few weeks ago. While driving home from work on the freeway at 60-65 at 2800-3000 rpm, I got on it to pass someone, and the truck lost all power. It would run fine until you gave it full throttle, then it would feel like the brakes were being applied. The motor would stumble and it would backfire thru the tailpipe. I made it home and parked it. Today I had a chance to look at it - opened up the top of the carb to check for debris in the float bowl, checked gas flow to the carb, fuel filter, accelerator pump, etc. All OK. Sprayed some carb cleaner in the carb and took the truck out for a ride. Same problem at freeway speed, but ran great around town, even with accelerating from 35 to 60 MPH in 3rd. Anyone have any idea what is going on? This problem came on suddenly, which leads me to think it may be something like junk in the fuel tank clogging the fuel line or something like that. All else seems OK. Have not checked ignition, but assume since it runs fine at all but freeway speed, it may be fuel related, just because of how it behaves. Thanks in advance for your help.
Brian
Brian