5.0L--Injectors Won't Fire
CantedValve, I got a kick out of your avatar, and especially the "Biodome!" reference above it. Haven't seen that movie in years, but it's a great one.
I'm using a stock 1991 Mustang mass air harness. The EEC does show power with the switch turned on; the fuel pump primes correctly, and according to a multimeter, all of the various pins on the back of the computer are powering up.
My relays are set up identically to the FordFuelInjection site. I have five: EEC, Mass Air/02, Fuel Pump, and Ignition. I wired them according to the FFI diagram.
Other than the relays, I tried to keep the wiring as stock as possible, even to the point that I'm still able to scan the car with the Self-Test plugs. Yesterday, I pulled the codes out of the ECM memory, but the codes present only pertained to the EGR and TAD/TAB/CANP solenoids that I removed.
What are your thoughts on the NDS issue? I remember wiring that, and I wasn't sure if I had it wired correctly.
Like you mentioned, it sounds to me like the ignition circuit is wired incorrectly, that the injectors are hot in the "run" position, but not the "crank" position, but I can't seem to find anything that's wired incorrectly.
Sounds like the only thing you have left from my list is the NDS... and I am not even sure that it will shut off injectors. What computer are you running? Manual cars ground pin 30, allowing the car to start. Automatic cars get 12V to pin 30, allowing the car to start. I have a A9P... automatic (which my car is also), so I will need the NDS switch that goes in the AOD (I have one, it is broken though). When the car is in Park or Neutral, the switch is closed, sending 12V to pin 30. When it is open, it doesnt sent the 12V. This is useful to a) allow the car to start, and b) set idle points depending if the car is in gear or not. I dont know HOW the switch acts. One way to eliminate it is to jumper that circuit closed and see if you retain 12V to the injectors. BUT BE SURE WHAT COMPUTER YOU HAVE. You will fry a manual computer if you put 12V to the pin thinking it is an automatic computer. A9L is the most popular manual computer... A9P the most popular automatic. Seeing as you are coming from a 1991 Mustang, it is very likely it is one or the other.
You are wiring your harness exactly as I am wiring mine. I am being a little more liberal with the modifications (putting in a switch to test codes, eliminating the smog equipment connections, eliminating VSS, etc.), but I did wire my relays in the same fashion as on FFI.com.