Im working on a 2.3 with 8 plugs.Starts fine at first then after 30 seconds or so it starts to idle as if on 3 cylinders,hit the accelerator and putters o2 sensor reads lean big time.Fuel presure at 35-42 never drops below specs,vac to the regulator pulled and responds by 5 lbs fuel presure,fuel filter changed ,plugs,wires,coil.I had this same problem huant me over 2 years ago and never could solve it,this one is killing me any help would be great.

 

I have no idea if it will be this simple for you, but i have a 95' ranger and had the same prob with it running like it was on 3 cyl and running lean. The prob was the sensor that plugs into the air intake right behind the air filter. The rubber boot holding it in popped out letting air get sucked in there. I'd say check thatout, its worth a shot. Hope its that easy for ya.