Re: 4.0L sputter
Maybe poor carburation or wrong fuel/air mixture? Could be timing problem also. Is it a consistent problem? What kinda gas do you use (octane rating). I just read in the "Jeep Owners Bible" that all straight 6 motors for Jeeps are designed to work with 91 octane and higher gas. You might try that. Mine sometimes chuggs or sputters a little when cold, but I'm pretty sure that is a choke problem (not functioning whatsoever). You might look at that too. I think mostly those symptoms are incorrect fuel mixtures, too much fuel, etc. etc. You could be on the right track by checking the 'puter like pimpin said.
If you are unsure, spend 35 bux and do a tune up. New plugs, change the oil, maybe some new plug wires, dist. cap, etc. That ought to help a whole lot.
Carl, Tampa, FL, 74 CJ-5
If a Jeep can't take you there, Think twice about going..