1986 F150 5.0 motor fuel inj. trucks runs fine at 35 to 45 mph. But after that it stumbles,and bucks and at times backfires. I have replaced all fuel parts,new new computer, rebuilt dist. tested tfi module,new ign module,new injectures,and tested for compression.New tune up wires plugs and pvc only I haven't done yet is EGR valve or sensors,did change catalytic conv.
Apr 21, 2008 at 10:25 PM