no spark

[mclaugj]

i have a 1985 f-150 4.9 I have no spark out of the sparke plug wires I have eplaced the ignition coil the picup coil the ignition control modula the dis cap and rotor the coild wire and plugs wires still no spark ??

[Max144]

Spark plug wires use to be made of wire, but they delivered out EMF and TV sets would pop and have spark lines on the display screen. They were changed with carbon fiber resistance cables to stop the disturbance. What you are finding is the cables cracking down enough that the spark is not being plugged properly and is moving along the outside rather of by the wire. It's time to change them.

[ASE AMD]

Bad connection/ wire. Check power and grounds to ign. Module. Or a bad a hall switch in distributor.

[cwargo]

I just went thru this with my 87 f150 5.0 I had to change the distributor after changeing relays and coil

[rhandwor]

Originally Posted by mclaugj

i have a 1985 f-150 4.9 I have no spark out of the sparke plug wires I have eplaced the ignition coil the picup coil the ignition control modula the dis cap and rotor the coild wire and plugs wires still no spark ??

Their is a relay that supplies power to the computer system. On later models it was along side the fender. It is the same size as the green fuel pump relay. Also their a ground wire next to the computer check this is tight. Sometimes in the pass. side kick panel. I've found both of these problems on Ford's of this vintage. Newer models top left side of safety wall.
Hold your finger on top of the relay and you can feel them pulse when turning key.