89 4.0 column shift auto .....bought it as my first Manche paid to much and spent to much .....the engine was not running well when purchased and I have little background info on it besides it came from ct and was hit from behind and parked for about a year.....I have done a major tune up on it replaced all vac lines, manifold gasket , rod bearing, oil pump, distributor, plugs, wires rotor , cap, cleaned grounds, cleaned idle air control, etc etc etc i have thrown every part at it and replaced many things I'm in of 2500 and have no chance of making money back,.........to get to the point it stumbles and hesitates when driving or revving the engine....idles just fine.......alittle history of my ownership.....I drove it and ran fine a few times one day I was pulling stuff in yard and the engine overheated because cooling fan relay failed to work and I knew nothing about jeeps at the time so it got so hot that the oil pressure dummy light began to flicker this is where the problems began .....never ran right after that day so the guy how sold it to me went to fix it put in the wrong distributor and it got loose and messed up the oil pimp drive distributor and the rod bearings so today we started it after long months of working on it and it runs fine but when revved it still skips it is timed correctly and my friend a good jeep mechanic did it......still can't figure out stumbling I have swapped fuel rail and injectors out of a working engine, fuel filter , checked fuel pressure and compression, he thinks it may be a computer issue .......any input would be awesome sorry for the long story