I've had a 91 240 (man. trans)for about a year-and-a-half that's consistently had a slight hesitation/stumbling on acceleration, especially when 'gooseing' the throttle from an idle. It seems somewhat worse over the last month. Replaced over the past year were plugs, plug wires, cap+rotor, fuel filter, air filter, rpm sensor, knock sensor, fuel press. reg., airbox t-stat, cleaned the throttle body, and took the injectors out to have them cleaned+flowtested and reinstalled with new o-rings. Also tried another fuel pump relay but no improvement. Any other places to check? Maybe the ground wire for the injectors? Maybe a weak fuel pump? Any ideas as to where to look next appreciated. dan in PA