I have a '92 f-150 4x4. Had a 302, but has been replaced with rebuilt 351. Has 3500 miles on new engine. The truck ran fine with the original 302 computer. Just recently started to have problems with stuttering stumbling above idle. Idles smooth, mid and top end is good but with part throttle accelerating from a stop, it stumbles. I give more gas and it goes away. I have replaced TPS, fuel injectors, fuel filter, fuel pressure regulator. No check engine light illuminated. Fuel pressure is good. Has done this thru several tanks of gas. What else could be the problem? !