1998 Ford Ranger stalling

Its a 98 ford ranger 2.5 just like the 2.3 not the new 2.5 mazda engine 5 speed man 2wd the problem is it will run ruff and sometimes stall worse when it is cold the problem is like this when first started it idles great then if I hit hi rpms apx 2,000 before shifting into 2nd then come to a stop it will run ruff and sometimes stall I can make it act up in the drive way just raise the rpms and hold them at 2-3000 let it return to idle and it shakes /run ruff for about 30 sec then returns to a good idle benn doing this for apx 40,000 miles but it never used to stall so it is getting worse I have done the flowing replaced timing belt (never jumped time) replaced all injectors replaced wires and plugs replaced iac checked oil psi when cold 75 lbs max thinking lifters were building up replaced all lifters disconected all vac hoses one at a time pluged vac I and ran engine at 2000 it contues to eather run ruff or stall made a gasket to plug egr valve and tested it remained the same checked fuel psi 50 -60 psi 55/60 ideling ruff I have watched timing to see if it returned when coming back down to an idle and it returned ok also sometimes after reving to 3000 rpms then let it stall then I try to restart it will crank but no start let it sit 15 seconds then it will start and run ruff then smoth out dont mater if I turned the key to off before trying to restart eather also I have never had to add coolant 1 dtc cyl #2 misfire please help UP DATE IT IS FIXED WHAT HAPPEND IS THIS THE INJECTORS PLUGED UP REPLACED ALL INJECTORS BUT STALLING CONTUNED REMOVED CYL HEAD FOUND ALL EXHAUST VALVES SUCKED UP INTO HEAD AND SOME CRACKING OF THE HEAD ALL FROM RUNNING LEAN FROM PLUGED INJECTORS REMBER I DROVE IT WITH THE SHAKE / STALL 40,000 MILES I NEVER RECEVED ANY DTC FOR LEAN NOR DID I EVER OVERHEAT THE ENGINE HAD THE HEAD REPAIRED AND I INSTALLED IT NOW IT IS RUNNING LIKE NEW