Hi there. New user here and boy am I in a bind. I have a 1991 f150 302 4x4 automatic. I'm not getting any spark from the coil. I rebuilt the distributer, replaced the tfi module and I even went out and changed the eec (ecm)box. Well I'm out about 160 bucks and still don't have spark. Please, please I know there is some one that has had this problem or knows how to fix it. HELP. Could it be the nutral safety switch? Leading up to total no spark condition there were several occations that the truck died and in a minute or two I did get it to start. Now no spark at all. You suggestion and Ideas will be much appreciated. "Lost in Missouri" dennis

 

No the neutral safety switch will not let the starter spin over. What Ya need to do is use a test light and attach it to a power source. Probe the negative side of the coil. Have some one spin the engine over. If it dosent flash then its a pickup problem or wiring problem. If it flashes, attach the clamp to a ground and make sure it has power on the power side when the switch is on. If all that works, then you need to see if there is spark directly out of the coil. If not then it sounds like a bad coil. IF you have spark from the coil check at the end of the coil wire. Good luck.

 

Thanks for your reply. I have done the coil wire test and there is NO FLASHING. I guess that I need to check the wireing,,. Is there any "easy" way to do this?

 

After looking at the wiring diagram, yuck! It sure don't look easy. If you're going to chase wiring, I'd suggest getting a diagram.

It appears that the power feed for the coil comes from the EEC relay. This should be located on the driver side fenderwell. It shows the power feed also connects to the TFI module and a capacitor.

The negative side of the coil shows going back to the computer. There is a resistor shown in this line.

 

I was headed in that direction. Was there power on the other side of the coil? Do you have injector pulse.. Need a noid light to test this... I am thinking either EEC relay or pickup in the distributor...I know you said u rebuilt it..