No power to Injectors during start

[samuel642000]

Figured I would ask this question here while I was digging through schematics and see if anyone could tell me off the top of their head.
1990 5.0 car will start and run just fine if I jump the solenoid but not off the key. It will crank if you use the key but will not start.
Got out the meter and have 12v with the key in run and 0v with the key in start.
Any best place to start?

I am currently locating prints to start at the beginning and trace the whole circuit.

TYA

[Captain Crawfish]

Neutral safety switch?

[JV106]

What’s the background on this? Did it just stop running or did you change something?

I have an EVTM for a 90. I can post/text you pics if you need them. I’d guess you either have a bad ignition switch, bad starter solenoid, or you have the starter solenoid wired wrong.

[JV106]

There’s a purple wire that lands on the very top of the starter solenoid that somehow supplies 12v crank only to the ecu.

[samuel642000]

Neutral safety switch?

jumped it to rule that out.

What’s the background on this? Did it just stop running or did you change something?

I have an EVTM for a 90. I can post/text you pics if you need them. I’d guess you either have a bad ignition switch, bad starter solenoid, or you have the starter solenoid wired wrong.

I bought it like this so I have no idea what all is done. Just one of those exciting things I get to track down. It's a mess of wiring and wiring is not a problem for me just can't seem to find what needs power when.

I assume my main problem is it is a 4cyl-5.0 swap car, don't know what all is the same wiring wise between the two.

But I will take those pics if you don't mind.

There’s a purple wire that lands on the very top of the starter solenoid that somehow supplies 12v crank only to the ecu.

I've got that plugged in.

[Stangs 4 Life]

If you witnessed it running before the information below will not apply to your situation.

The 1990 model year wiring harness is pinned differently than the other years. I had this same problem on a 1990 conversion and fixed it by getting a 1990 engine harness.

At the time, it was said that I could move (repin) the existing harness but I just sold it when I got the correct year model part rather than risk damaging it.

[JV106]

Just let me know what circuit you want and I’ll try and post some pics. There’s 200ish pages of circuits in this book.

[hotrod66stang]

If this is the black 4-cylinder conversion in SW FW, there is a "kill switch" on the side of the console by your knee that a previous owner installed that controls the fuel pump. I went to look at the car the day it was listed and passed. The guy cranked it up and it ran, but not very smoothly.