Engine Performance problem
2001 Ford Ranger 6 cyl Two Wheel Drive Automatic 155000 miles
The temp gage failed motor locked down; tryed to restart motor not kowning that and battery shorted. I had the motor replaced with remanf. With new wires, plugs, ignition coil, and CKP. Service engine light came on when I got the truck home about 10mi. The shop looked a the codes and said that it said random misfire. They reset timing drove truck no light. U/P truck get home light returns and it did seem like it was missing on long slight grade. I returned to shop they checked the truck and said that the camshaft position rod needed to be replaced; that was done and now when you are in drive and it shifts from first to second gear about 3000RPMs it seem like it is reacting as though you were in park revving the engine and the RPM limitor is trying to restrain the engine and the light has returned. They want to replace the PCM now. What do I need to do to stop the misfiring and clear the code.
Engine misfiring could be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.