Hello, I could really use some help this is driving me nuts. I have read 100's of forums of the same symptoms and it appears to always be a different fix. Here goes, I have a 1993 F250 XL with the 5.8 EFI when I start it the idle after initial high idle it will lug down as normal but then it will kinda rrrrahh, rrrrahh, rrrrahh, kinda a up and down consistent. Driving it it will buck and shake when you let off the gas. Starting out from a stop it just revs up and down like it can't find the gear if I lightly press throttle or let up then lightly press it will catch and go fine in till about 50 mph when I let off it will buck hard on . I checked codes several times and keep getting the pass 111 and the 10 separator. A couple times checking codes I did get a lean code I believe it was 172. I have lots of sensors from a parts truck and have tried changing everything. First changed plugs, wires, cap, rotor, distributor retimed, changed the coil, icm, tps, IAC, EVR, MAP, changed the Alternator, Radiator, installed a new negative ground wire, cleaned all ground straps, dropped the tranny pan, changed filter and fluid, new fuel filter, new vaccume lines, changed pcm with the spare, I also opened both and looked for the leaky capacitors or burned circuits but all looked good. Also changed 02 sensor, and I know there is more but can't think of it all right now. Made some improvements but bucking and jerking is still there. All the parts I changed I did 1 at a time reset the pcm, and when nothing changed I swapped back original part. I'm totally smashing my head here. Another thing if I take out the shift fuse and unplug the egr vaccume then I can drive it. Can do 90 mph no problem on freeway when up to speed it drives very well unless you hit a steep hill feels like it comes out of gear and will just rev when pressing gas. Still hunts for gears off the line and revs up and down but doesn't buck and shake like when plugged in. I removed EGR valve put in backing plate capped the vaccume and it still did same thing. I think I need to start over from scratch. Oh I routed plug wires the way the tsb said to run them as to not have cross spark. I need this truck for work to feed family and would like to get it fixed.. please some of you old school Ford guys help me out.. I've been reading the forums for years this is first time I couldn't fix it..

 

I don't see you mentioned ECT and MAF.
A bad MAF has ALL the combined symptoms you mentioned. Just disconnect battery, unplug MAF electrical connector, wait 10 minutes, reconnect your battery ground and drive for 10 minutes or so. You may experience lack of power when it's in limp mode because MAF is unplugged for diagnostic purpose, if your idle should be better and no hesitation and no sputtering, then your MAF is probably at fault. Don't be surprised your truck might have more than one issue.
For ECT follow the procedure below, don't just replace a new ECT. If the electrical connector has corrosion which can cause bad reading, clean that.