This week while sitting at a light my car began to stumble and idle very roughly, the car had been running like a top until that moment at the light. My first thought was a problem with the ignition module/coil pack. I switched those out with another set I had, and the car calmed down and idles/revs beautifully now. When I went for a test drive, I still noticed an acceleration stutter from stop. When on the hwy in cruise mode it runs fine, it'* just a slight noticable stutter on acceleation from a stop. Late last summer I replaced the fuel pump (first time in 220k); filter, and pressure regulator, balancer, timing chain, interrupter magnet and gears.

What else should I be looking for.....being OBD I my AutoXray 6000 scanner only shows minimal information. Additionally, My checkengine light is NOT on.

Thanks :?:

Same problem, except now mine has become an almost constant hesitation/misfire, no codes still as of yet, I will post if I figure it out.

Check vacuum lines, especially the line going into the top of the upper intake manifold. It'll be the line that comes off the fuel pressure regulator. On the '91 (and maybe later models) it goes into a black plastic diverter that'* held in by one bolt. The gasket under that has a flare for drying out and cracking/brittle. Replace the gasket, if you can find one, OR make a gasket out of gasket material. This will seal any air seeping under that into the UAI.