Help injectors aren't firing

[crue]

I have a 92 Ford Explorer with a 4.0 and manual transmission. I replaced motor now it will not start. It runs on carb cleaner. I've narrowed it down to my injectors aren't firing. I've checked all my grounds. I've swapped out the computer and most every sensor. I'm carrying 40 lbs pressure at the fuel rail. It really confuses me, both sides of the injector plug have 12 volts. Help

 

[Turdle]

Check the signal wire from the crank position sensor. It is easy to stretch that one during the engine swap.

The ECM will send a "low" to one side of the injector to fire it so the 12v on each side is a good sign. You have narrowed it down to an issue with the signal

 

[crue]

Thanks I will check this out. I'll let you know if this works.

 

[crue]

I checked my crank sensor wire and it is good. If you have any other ideas I will try them. Thanks.

 

[Turdle]

OK
Now, disconnect the harness to the injectors. You can do this at the connector plug near the alternator.

You will find the red 12v line, also, the tan and white signal lines in the connector.

Measure across the red to tan, then the red to white on the ECM side of the plug.

With the key on you should read 0 volts across them, but you should read 12v on each when referenced to ground.

While cranking you should see 12v pulses across red and white, also the red and tan. The white and tan wire should switch to 0 volts while cranking when referenced to ground.

 

[crue]

I checked the red,white and tan wires with the key on. The red wire has 12v but the white and tan wires has no signal with or without a ground. When cranking there is still no signal.

 

[Turdle]

ok, this is good stuff, as earlier you stated there was 12v on both sides of the injectors--when the harness was connected.

Now connect the plug, and recheck the pins.

if the 12v comes back look for a short circuit in the injector harness---

 

[crue]

With the plug reconnected the injector plug has 12v on both sides when grounded. I replaced the engine harness when I first started this. I have also checked the harness back to under the air cleaner. I will strip the conduit back to the firewall and see if there is any shorts.Thanks for all of help. I let you know if I find anything.

 

[crue]

I rechecked the wires from the injectors to the computer and found no shorts.I was thinking maybe the plug on the EMC side could be bad?

 

[crue]

I rechecked the whole system again from injectors to ECM, still can't find no shorts or anything wrong. HELP I'm out of ideas.

 

[crue]

I got the truck running! It was pluged injectors. The engine sat for 2 or 3 years so I am guessing the fuel went bad and caused this. I want to thank Turdle for all of your help.THANK YOU! See you on the trails. crue.

 

[Turdle]