My truck is dumping fuel pressure as soon as the key is off. I found a similar thread and followed it along regarding testing the injectors for ground short and "low and behold" the test light showed a short on the tan wire side. I got my meter and tested and I'm showing continuity between the tan and all the injector red wires all the way back to the large plug by the battery. I isolated that section from the plug to the PCM and it's not showing the same continuity.

So should i strip the harness covering and start looking for the issue or am I way off base here???

As always thank you in advance.

 

What year Ranger?

1995 and up used sequential injection, so with a V6 there would be 6 separate "ground wires" one for each injector
Earlier systems were Batch fire injection, so 3 injector share 1 ground wire, so there are only 2 injectors "ground wires" for 6 injectors

Tan wire would show continuity to common Red wire if any injectors are plugged in
An injector is just a coil of wire inside, maybe 15ohms resistance, so shows as a connection/short

With fuel pressure at 0psi
Turn on the key
unplug and plug in the injector wire connector in question, you will hear a "click" if that injectors ground wire is shored to ground, its not quiet, or if injector has an internal short to ground, which is tough since its plastic

The Red wire will have 12volts with key on, the red wire is just daisy chained from one injector to the next.

The computer grounds an injector to open it

So you can use a test light or volt meter on a DISCONNECTED injector plug to see if you get 12v with key on, only use the 2 wires on the connector for the test, you should not see 12v, if you do then that non-Red wire is a ground

 

Ahhhh, Got it. I DID leave one injector plugged in. Once i unplugged it.... My "short" had disappeared. I pulled the return off the FPR and cycled the key and gas shot up about 3 feet! I reconnected it and put a clear bottle on the return at the tank and jumpered the fuel pump with the test plug and the bottle filled up immediately.
I put the old FPR back on and think i made some headway... shut the engine off and pressure held. ANd,,,, the truck started immediately... no long crank. It kind of lopes at an idle and still smells rich, but i think i made progress today.
Now if i can figure out it runs better without the IAC and TPS unplugged.... I think i will cry tears of joy!!!

Again, Ron. you are an awesome diagnostician. I truly appreciate you and your knowledge.

Thanks.

 

Good stuff

So vacuum line at FPR is dry as a bone now, correct?

Thanks for the update and the FIXES so far