4.5L Fuel Pressure Readings.

[Keith Browning]

I would like to know what you guys typically see when testing fuel pressure on 4.5L LCF's. The Performance Diagnostic Procedures states: Enter 413.6-482.6 kPa (60-70 psi) for the KOEO fuel pressure and the fuel pump discharge pressure, 276 kPa (40 psi) for the low idle fuel pressure, 345 kPa (50 psi) for the high idle fuel pressure, and 20.0 kPa (6 in Hg vacuum) for the fuel pump inlet restriction specifications on the Performance Diagnostics form. This is vastly different from the specs for a 6.0L for example.

[Bruce Amacker]

IH states:

 

Key On Engine Off

Engine fuel pressure (min)

310 kPa (45 psi)

 

Engine fuel pressure (max)

448 kPa (65 psi)

 

 

Engine Cranking 20 seconds maximum crank time per attempt. Wait 2 to 3 minutes before repeating.

Engine fuel pressure (min)

310 kPa (45 psi)

 

 

 

 

 

 

Low idle, stabilized engine operating temperature Readings taken at 16 °C (60 °F) ambient temperature.

 

Engine fuel pressure (min)

310 kPa (45 psi)

 

Engine fuel pressure (max)

448 kPa (65 psi)

 

 

 

High idle, stabilized engine operating temperature

Engine fuel pressure (min)

310 kPa (45 psi)

 

Engine fuel pressure (max)

448 kPa (65 psi)

 

 

Full load, rated speed on chassis dynamometer or highway, stabilized engine operating temperature

Engine fuel pressure (min)

310 kPa (45 psi)

 

Engine fuel pressure (max)

448 kPa (65 psi)

 

 

 

HTH

 

 

Does yours have the recall/update with the FPS screwed into the FF housing?

 

[Keith Browning]

Does yours have the recall/update with the FPS screwed into the FF housing?

Ford never recalled trucks for that and no, there is no FPS.

 

I have a truck in with 35 PSI KOEO and 43 PSI at idle. I am getting conflicting data from Ford on this from the PCED to the Hot Line. Seems a tad low to I want to address this while I am replacing all 6 injectors. I am replacing the regulator first.

 

I just want straight answers and I am not getting them... except from you of course.

[DieselD]

That sounds low for sure

 

The last one I had I was pulling over 50psi KOEO

[Keith Browning]

Here is the Navistar fuel pressure switch bulletin. Ford never released this to the best of my knowledge. Is this something that would be plug and play on the Ford LCF's?

 

Thank you Bruce for the bulletin!

[Bruce Amacker]

Here is the Navistar fuel pressure switch bulletin. Ford never released this to the best of my knowledge. Is this something that would be plug and play on the Ford LCF's?

 

Being that the update requires a special flash, and flashes are VIN specific on IHs, it seems to me that this would not work on a Ford without special dispensation from the Pope, right?

 

[Keith Browning]

I am thinking that if you have access to NETS (which I do) and the option comes up then we should be capable of the update. Getting PAID to install this from Ford would come under the category of "not in this lifetime." Obviously the Navistar guys have a green light. Customer pay? Why not.

[blown99]

Do you want an IH VIN that has this recall done to it? The "old" spring was a 40 psi spring. The new blue spring is 60 psi. I usually don't see much of a variance in pressure on a properly working system between idle and full load. The reason for the recall was the UPS chassis were having issues pulling fuel below 1/2 tank. IH wanted to alert the driver if there was an issue to save the injectors - the reason for the pressure sensor and calibration to turn on the feature.

You would have no problem just installing the blue spring kit and running the engine without the updated calibration.

[mchan68]

Reading through this thread makes me wonder if installing an FPS wouldn't be a good mod to do on a 6.0L engine, since fuel pressure is the only data that is not monitored and requires measurement using a manual gauge. Unfortunately, I don't see a way to reflash the PCM that would be able to "add" this to the list of PIDs that can be monitored.

[Alex Bruene]

I haven't read the bulletin, but isn't the switch just an on/off switch? I don't recall being able to read the fuel pressure as a PID on LCFs that came with it from the factory...

[blown99]

Yes, it is an on off switch, single wire.