So the truck started running like crap and missing at stop lights and when in low idle. Once the rpms are above 2000 it seems to quit and run smooth. Truck has 140,000. Originally threw a code for misfire cylinder 6, later it pulled random mis-firing. Put new plugs, wires, cap, rotor, whole fuel-injector unit, distributor gear.... Still has rough idle. Has good compression and I have no idea where to look next....