I did a fairly thorough search trying to solve this problem before I decided to write this post. So when you try to start the truck the starter spins the engine but there is no spark. If you run a hot wire directly from a constant 12v source to the + side of the coil it will fire up and run like normal. You can disconnect the constant hot jumper from the battery while the truck is running and it will continue to run until you cut the key off as normal. I replaced the ASD relay and I also checked for a constant 12v at the "big red wire" the fuseable link wire on the ASD connector and have 12v. Any ideas? I'm thinking it's maybe PCM related but wanted someone's opinion who has actually tinkered with these things. I plan on going with a 4bll in the future anyway so if it's a PCM problem I may run that constant hot on a toggle inside to get me by for a while. Just wanted to possibly fix it, if it was possible the correct way. Thanks in advance!!

 

Did you check voltage at the coil with meter? It should have power the same time the fuel pump is running. It's on the same circuit. Might be in the wiring after the asd somewhere.

 

Yup!! 0 voltage with the key in the on position, but once you start the truck you can disconnect the 12v jumper wire I made from the coil to the battery and the truck powers the coil with 12v. It only doesn't have power when the engine isn't running/ the key is on. Seems strange, I'm guessing the ECU is powering the coil/fuel pump after start up?!!