hello, i need some help. ive got a 1997 f250HD old body style with a 460. sometimes it starts and runs fine, sometimes it will die and wont restart for a while, sometimes it wont start at all. when it dont start, its got no spark, ive replaced the ign switch, ign coil, has any one had this problem? thanks waller

 

I have to think back as to whether your vehicle has a distributor. If it does there is a shutter wheel and what in effect adds up to a pick up coil that triggers the ign module to produce the spark signal for the coil. Do you have voltage available at the coil ign terminal when you lose spark? The other terminal of the coil should have a blinking voltage when attempting to start. If not , in the first part you should have voltage available to the coil whenever the ign is in the on position. The varying signal to the other side of the coil creates the spark and comes from the ign module and the dist signal. Let us know where you stand with this.

 

I'm having the identical problem with my 1997 Ford F-250. Did you find the answer? I would appreciate knowing. Thanks, hodges

 

It could be a relay. I had an old Exploder and it would have a similar issue. When I had someone tap on the relays as I tried to start it, boom, it would light right up. I eventually just got a new relay... good luck 2009 volkswagen cc vr6 4-motion review

 

There are many causes for this. I could think of anything from a fuel pump to wiring. One area that no one ever thinks to look at is the old Check Engine light (or SES or whatever ford's acronym for the day is). It should come on at key on, eng. off, before cranking. It should go out when the engine cranks (then either stay out or on, depending on faluires logged in the PCM). If it stays on while cranking, it means the PCM doesn't see the crank turning, which technically means it isn't seeing PIP (profile ignition pickup; or, for the less engineering involved crowed, crank. position sensor).