94 dodge starts and runs only while starter is engaged
 

Well, I put the new engine in my truck, and everything was fine, started up smoothly many times, today, I fired it up to roll it out of the shop to dust it off (we were going to paint it), and while backing it back into the shop it suddenly died, after that it would start, but only run while the starter was engaged.. I know it's the "hold up" circuit for the injector pump that's not working, while the "pull up" circuit is fine. I fiddled with the wiring and whacked the two firewall relays, but that didn't help, fuses under the hood are fine, haven't looked at all the fuses by the drivers door yet though. Does the computer control that relay through an automatic shutdown circuit? or does it go straight from the ignition hot?...

What are my most likely culprits?

Anyone?

And has anyone put power mirrors on a truck that wasn't OEM power mirrors? wiring harness in the doors appears to be there, plugged everything in and they aren't working.. is there some underdash wiring missing?

Solved, it was a short, causing an in-cab fuse to blow. Unrelated to that the power mirrors mysteriously started working.. who knows why but I'm OK with it :)