99 F-350 Diesel Cutting Out Under Load

My 1999 F-350 diesel w/ 200k cuts out under load at a certian position in the gas pedal. It has a six speed in it but it is almost like it is looking for the passing gear. I bought it used so it could have a different computer in it I guess. If you push down farther or let up on the pedal it takes off just fine. Is the a way to bypass a passing gear on the computer?

I would bet that the pedal switch is going bad. I don't know how to test to see if it is, but i'll do some more research. About what RPM does it cut out?

Do you have any check check engine lights? Couple of things to look at would be the CPS. A friend of mine also said that his was cutting out because of a loose connector on the valve cover.

TRY cps first but most likely the throttle postion sensor, You will have to replace the pedal assembly if its that, which I bet it is.