I have a 1987 F-150 that was purchased new in April 87 by my father and has 130,000 mostly old-man driven miles. He gave the truck to me at 120,000 miles because it had become hard-to-start. The first thing that I did was to have all 3 fuel pumps replaced. It has one in each of the duel tanks and one main pump on the driver's side frame rail. This helped the problem but didn't cure it. During the next year, I replaced the timing chain, including removal of the oil pan to clean and remove debris from where the chain disintegrated, as well as the water pump, radiator, all hoses, serpentine belt as well as such minor things as fuel and air filters. The truck had developed an intermittent problem of running bad. It would run fine for sometimes two or three weeks at a time then suddenly develop severe spark knock, loss of power, and would finally go dead in traffic. After a few minutes it would re-start and gradually run better until it finally became "normal" again. But a few days or weeks later it would do the same thing again. It didn't seem to be effected by weather or any other conditions. During the year that this happened I replaced the spark plugs, distributor cap, plug wires, replaced all the fuel pumps once more, added gas treatments to clean the fuel injectors, replaced the fuel pressure regulator, the computer (which corrected the hard starting, but did nothing for the intermittent bad running problem), and the fuel-splitter on the frame rail, all to no avail. Finally, the distributor, coil, and ignition module were replaced. This was done all at the same time, so I'm not sure which one corrected the problem, but I suspect it was the distributor. My mechanic says he thinks it was the pickup coil inside the distributor. In any case, since it took over a year to find and correct this problem, I thought I would share with other readers who might have similar experiences. I was about ready to trade the truck off because so many things had been tried and nothing helped. Now I can again trust the vehicle on long trips and enjoy driving it again. Maybe my experience will help others who are having the same problem.


Alan L. Leonard