Just installed a new AMC head and its running decent but the engine kinda of stutters and hesitates when initially accelerating. It will do this when just sitting in neutral. And it will run pretty rough when idling under 1000 rpms. I figured it was a vacuum leak but did the carb cleaner trick and couldnÆt notice a change anywhere.

This sound familiar to anyone?

ItÆs a 88 Trooper 2.6L 4ZE1 AMC head

Is the EGR Valve functioning correctly....
Still sounds like a vaccum leak!!!! keep looking!!!s

Valve adjustment ?????

Yeah, itÆs acting like a vacuum leak but I couldnÆt find any. IÆm going to try and figure it out this weekend. Valve adjustment would cause something like that?

Anyone know what I need to do so I can check for computer codes? Is there some diagnostic tool I can buy?

Thanks.

Welcome to the 2.6 perennial mystery club. Are we talking hesitation on a cold start or are we talking a warm engine? I'd start by verifying all the vac hoses are in-place and tight, move on to the EGR circuit to determine that it's not fouled and conclude with plugs, wires, distributor. This is presuming you have timed the engine and adjusted the valves as part of putting it all back together. It's a common problem which frequently defies instant solutions. It's a process of elimination. If the mechanical side doesn't yield a solution the electronics are next.

Look for something delivering too much fuel or not causing an adequate burn (like timing). If it's bad, like hardly driveable, it's probably timing or very poor ignition. If it's slight (annoying) then look at something that would cause it to run rich, i.e. bad MAF, coolant temp sensor, stuck injector, etc.

If it's a crappy idle I'd look at EGR and the vacuum issues that everyone has...