[b.cook]

And your fuel pressure is where it should be , fuse and all are wright on ? Gov Holmes

I haven't put a gauge on it yet, but it fills the fuel bowl very quickly when the key is on.

 

[Jax]

I haven't put a gauge on it yet, but it fills the fuel bowl very quickly when the key is on.

Then that probably isn't the problem.

Unfortunately I don’t have the old one. What are the chances of a brand new Motorcraft going bad?

Well . . . I would say not but they are made in Mexico and I have had some IPR issues.

You could buy a cheap, chinese crap and use it as a troubleshooting too. It should at least read something and they run about $25. If you do get a reading, you take a picture and return your Motorcraft for a new one.

If it doesn't read, you know you have a wire issue.

 

[Jax]

While you were looking in the fuel bowl, the filter wasn't dark, was it? (ruling out o-ring leak on injector)

Did you do the KOEO (key on, engine off) tests? And do you run a tuner?

 

[Jax]

Also, did you read that ICP link I posted?

Did you do this test?
With your engine running, pull the connector, disconnect your 7.3 ICP pigtail. This causes the PCM to deliver a default ICP value of 725 PSI at idle. As apposed to the stock setting of 500-550 PSI at idle. There should be a noticeable difference in idle when you unplug your ICP.

Photograph your dashboard.

 

[Jax]

Here is a link with Ford test data. Try these measurements.

ECSD - Injection Control Pressure (ICP) Sensor -...

Injection Control Pressure (ICP) Sensor Courtesy of: Ford Motor Company SIGNAL FUNCTIONS The Injection Control Pressure (ICP) sensor is a variable capacitance sensor that when supplied with a 5 volt reference signal from the PCM produces a linear analog voltage signal that indicates...

www.thedieselstop.com

 

[b.cook]

So just double checking my logic.

If the fuel bowl levels are good.
The IPR is building pressure on crank.
The ICP only builds pressure when unplugged but still no start.
There are no codes.

That unfortunately leads me to think PCM.

Am I correct in that thinking?

 

[b.cook]

While you were looking in the fuel bowl, the filter wasn't dark, was it? (ruling out o-ring leak on injector)

Did you do the KOEO (key on, engine off) tests? And do you run a tuner?

No the filter was very clean.

 

[b.cook]

Also, did you read that ICP link I posted?

Did you do this test?
With your engine running, pull the connector, disconnect your 7.3 ICP pigtail. This causes the PCM to deliver a default ICP value of 725 PSI at idle. As apposed to the stock setting of 500-550 PSI at idle. There should be a noticeable difference in idle when you unplug your ICP.

Photograph your dashboard.

Unfortunately it won't start so I cant do any tests while running.

 

[Jax]

So just double checking my logic.

If the fuel bowl levels are good.
The IPR is building pressure on crank. You don't know this.
The ICP only builds pressure when unplugged but still no start. The ICP does not build pressure. It only reports if pressure is building. Since - when plugged in - there is no report of pressure, then you need to replace it with a known good to test it. That is why I suggested a cheap chinese part from an auto part store. $25 is cheap for a tool.
There are no codes.

That unfortunately leads me to think PCM. It is looking very iffy.

Am I correct in that thinking? Consider my notes . . .

You really do not know what your IPR and HPOP are doing since the ICP sensor is not reporting properly.

Please try the electrical tests from thedieselstop thread I posted.

 

[b.cook]

Here is a link with Ford test data. Try these measurements.

ECSD - Injection Control Pressure (ICP) Sensor -...

Injection Control Pressure (ICP) Sensor Courtesy of: Ford Motor Company SIGNAL FUNCTIONS The Injection Control Pressure (ICP) sensor is a variable capacitance sensor that when supplied with a 5 volt reference signal from the PCM produces a linear analog voltage signal that indicates...

www.thedieselstop.com

I did these tests and the only one off was that B to ground was 300 ohms not >1000.

 

[Jax]

Ah! Time to chase wiring! With the Brown/White one that low, you need to find where it is shorted. That could be the cause of all your problems (fingers crossed).

First, make sure you check the plug and see if any of those short to the Brn/Wht. Could be a messed-up plug.

Then check your work.

3rd, unscrew the 10mm that holds the wire harness into the firewall / PCM. Once unplugged, check your Brn/Wht to ground again.

If there is a change, and Brn Wht is >1000 ohm, See if there is any damage. If not, your PCM may be toast.

If no change, unscrew the 10mm that holds the plug to the engine harness that is over the left valve cover.
Check the Brn/Wht again. If no change, the short is between the valve cover and PCM plug
If there is a change, the short would be in the IPC sensor plug and the Valve cover plug.

Happy hunting!

 

[b.cook]

And your fuel pressure is where it should be , fuse and all are wright on ? Gov Holmes

Yes fuses are all good and pressure to the fuel bowl is good.

 

[b.cook]

Ah! Time to chase wiring! With the Brown/White one that low, you need to find where it is shorted. That could be the cause of all your problems (fingers crossed).

First, make sure you check the plug and see if any of those short to the Brn/Wht. Could be a messed-up plug.

Then check your work.

3rd, unscrew the 10mm that holds the wire harness into the firewall / PCM. Once unplugged, check your Brn/Wht to ground again.

If there is a change, and Brn Wht is >1000 ohm, See if there is any damage. If not, your PCM may be toast.

If no change, unscrew the 10mm that holds the plug to the engine harness that is over the left valve cover.
Check the Brn/Wht again. If no change, the short is between the valve cover and PCM plug
If there is a change, the short would be in the IPC sensor plug and the Valve cover plug.

Happy hunting!

Ugh. I will certainly do that. (Happy Hunting, Ha! I see what you did there)

I may also get a PCM from a U Pull and pay that has a couple of same-year/engine trucks on the lot. They are only $15, so a quick swap could tell me if the PCM is indeed the issue. If it is, I can then pony up for the new PCM unit.

 

[matthewd11]

Have you verified BASE oil pressure? Have you done an injector buzz test?

Maybe i missed it but I don’t see you saying you didn’t. Your ICP value unplugged is inferred.

 

[Jax]

Ugh. I will certainly do that. (Happy Hunting, Ha! I see what you did there)

I may also get a PCM from a U Pull and pay that has a couple of same-year/engine trucks on the lot. They are only $15, so a quick swap could tell me if the PCM is indeed the issue. If it is, I can then pony up for the new PCM unit.

Do you know what (code 3-letter) is on your pcm?

I would send your PCM to DTC before buying a new one.

 

[JMFS]

I did these tests and the only one off was that B to ground was 300 ohms not >1000.

This is probably the issue. ^ I’d try unplugging your fuel bowl heater as a quick and free test… just in case.

 

[b.cook]

Have you verified BASE oil pressure? Have you done an injector buzz test?

Maybe i missed it but I don’t see you saying you didn’t. Your ICP value unplugged is inferred.

I did an injector buzz test and they all passed.

 

[matthewd11]

I did an injector buzz test and they all passed.

Have you verified adequate base oil pressure?

 

[b.cook]

UPDATE:

Sorry had some heavy snow the past few days so I had to winch the truck into my shop so I could test out the wires.

Do you know what (code 3-letter) is on your pcm?

I would send your PCM to DTC before buying a new one.

I opened up the harness so I could trace the wires and was able to verify that I had good continuity for the three wires from the ICP to the PCM plug.

ICP GY/R --> PCM Pin 91 -- Test to .3 Ohms
ICP DB/LG --> PCM Pin 87 -- Test to .3 Ohms
ICP BR/W --> PCM Pint 90 -- Test to .4 Ohms

So I'm assuming that means I'm likely looking at a PCM issue? Where could I send it for DTC?

 

[Jax]

Did you verify the base pressure?

The ICP may be reading correctly.

The wire reading from the plug to the PCM should be zero. It is just wire, and should have NO ohms.

So I'm assuming that means I'm likely looking at a PCM issue? Where could I send it for DTC?

Link is in post 16.