I know a lot of you are also on the Ranger Station site but I'm hoping someone here has an answer. I rebuilt a 302 out of a 99 Explorer and put it in my 03 Ranger. The problem we are having is it won't start due to the PCM not pulsing the injectors. We thought it may be the PATS but we swapped everything from the Explorer over and it still doesn't work! We can get it started and running using a spray bottle with gasoline so spark is good. We've tried unhooking the TPS and that didn't work. We are at a loss for reasons why the injectors won't work! Can anyone think of something that may cause this problem?

 

Does the fuel pump come on for the 2 seconds with Key ON?
Its not quiet

Does it have a 3 wire Cam Sensor or 2 wire Cam sensor?
Unplug it in either case and try to start it

The crank sensor is used to time spark and usually fuel injectors, at least for start up, then Cam sensor takes over for fuel injectors, unless its not available

I assume injectors have 12volts with key on?

TPS is unplugged, but test center harness wire voltage, key on, should be 0v, if 5v then shorted wire in harness

 

The fuel pump comes on each time the key is turned on. I'll have to check on the rest and get back to you.

 

Could be Cam sensor issue then not PATS if fuel pump works

Ford change software around a bit in the late 1990's

I know some of the 3.0l Rangers would get a no start from no injectors if Cam sensor pulse was absent with cam sensor connected
The "thinking" for this was that the Cam sensor synchro is ALSO the oil pump drive, so..........if it wasn't turning, sending a pulse, then you do NOT want engine to start, lol, with no oil pump
Over thinking it in my opinion

I am hoping disconnecting CAM sensor will cause computer to switch to Batch fire fuel injection

You can test 2 wire Cam sensor with volt meter set to AC volts, same as testing crank sensor, should get .5vAC when engine is cranking

3 wire is harder to test, hall effect type, you get a DC 0v/12v pulse from center wire, and have to test it while 3 wires are connected

You have to use the type of Cam sensor that the computer was programmed for, 2 wire is variable reluctance(AC), 3 wire hall effect(DC) so the signals are not interchangeable, i.e. its not fixable by splicing wires, lol

I think Ranger V6's all changed to 2 wire in 1999 not sure on Explorers

 

The Cam Sensor/Synchronizer are all brand new. I know that doesn't mean it's not a bad one but chances are low. I replaced everything that was replaceable on the engine!

 

2 wire or 3 wire Cam sensor?

Do you have an OBD reader that can view live data?

The Bluetooth versions are $30 and can be well worth the money as they work on any vehicle from 1996 and up
You may need to spend $5 on the Torque APP but worth it

You could see what the computer sees from each sensor, key on

Chances are low you would have this much trouble too, lol
Occam's Razor says simplest answer is usually the right answer
Do you have the old cam sensor?

 

It's a 2 wire set up with .5V like you said. Disconnecting it did not work. My mechanic has his Snap-On that does everything but drive the vehicle! Not sure what he has looked at though.

 

Then out of ideas

ODB would set a code if crank and cam sensors were not in sync

PATS disables fuel pump and injectors, and on some years starter motor, so that is not it, if fuel pump works

TPS can disable injectors but NOT after RPMs are above 400, so starting with gasoline manually would take that off the table, i.e. it should stay running after is starts

Gasoline in the tank is good, so your not trying burn water, lol

And no injector grounds from PCM

System is just not that complicated, so we are missing something

 

Turned out to be a bad injector tucked under the intake plenum where we could not get to in order to test it. Had to pull the intake off but we found it. Fires right up once the injector is disconnected. It was so sweet to hear the engine fire up for the first time. Especially with open headers!

 

Good work

Thanks for the update and the FIX