i am in the the process of swapping out my 3.1 to a 350. i have the ecm and wire harness from a 5.0 car. i have 95% everything hooked up and im down to starting it up. but when i turning the key on i hear no fuel pump, and starter doesn't even crank. i checked all the fusible links at the red wires after the links and they get voltage. i put power to the purple wire for the starter and it turns over. so the starters good. i put power to it all the way to the crank fuse ant it still works. and when its turning over it tested for spark at the coil and get nothing. and i don't even get a security when i turn the key on. is it a vats issue? vats worked with the 3.1 in it.

The harness I bought is for a 90-92 305tbi

Does anyone know the difference in the c100 plug in the 90-92 v6 versus v8?

 

That swap us plug and play, I just did one.
If you have no power to the coil it is a fusible link problem.
Just went thru that too.

Do the guages work on the dash?

 

Why would you assume a ecu from a 5.0 would work?

 

Actually the gauges did work. But no check engine or security light came on.
So I ended up going to the junk yard and getting a 1992 roadmaster ecm. After grounding the blue wire at the c207 plug, the security light comes on now as well as the service engine. The fuel pump works and sprays cones out of both injectors. It also cranks now but I still get no spark past the coil. But it gets 12v at the coil pink wires on both sides.

 

Edit. I ran a test light to the white tach wire and it has constant voltage when plugged into the coil. But when it's unplugged it's dead. Its like the coil is completing the circuit from the pink wire to the white wire when plugged into the coil. Is the tach wire supposed to be hot?

 

Is this a good donor for my 89 v6 firebird?
https://richmond.craigslist.org/pts/5517393241.html

 

The motor will work just fine. You will still need a camaro or firebird harness and a LO5 ECU.

 

update. i changed the pickup coil and still no spark. everything is hooked up the way it is supposed to be is the any pins on the ecu that give a spark signal that i can test?