I have a 93 YJ with a 3 speed auto tranny. When I first start it up whether it's in the morning or after the engine has cooled down, the engine will spudder almost to the point of stalling. It doesn't stall, instead it will idle up to about 1500 rpm. It's usually idling at just under a 1000 rpm. This will occur until the engine has warmed up a bit, then it seems to go away. However sometimes even when the engine is fully warmed up and I've been driving for a while, when let's say I come to a stop light, the engine will spudder a bit, like it is starving for fuel. It will then idle high and actually jump forwad a bit. I have cleaned the throttle body, added fuel injector cleaner and such. The fuel filter has been replaced. Not sure what it could be?