[agomez]

okay can someone tell me how this thing actually works? The reason I ask fuel was leaking from the side of the filter canister and when I changed out the ipr the plug gaskett was gummed up. The wires were wet but not corroded I think the back of the plug were the two wires come together are touching causing the ipr to not operate correctly. So should I here a click or some tupe of small noise when the key is turned on to actuate the solenoid on the ipr? Can I remove the ipr and turn the key and see the pin shoot forward or is this not reccomended....just thinking out loud...also I am ELECTRICALLY CHALLENGED can I measure voltage at the plug if so can you give me an example on how to test? I am close to figuring this hot start problem I think and the leaking fuel on the plug has to have something to do with this....thanks....

edit: does the oil drain back into the pan if the pin on the ipr is not engaging?

 

[Patrick Feeley]

Here ya go, right from the factory manual:

Pressure control in the injector control pressure system is closed loop. It is controlled by the injection pressure regulator (IPR), the injection control pressure (ICP) sensor and the strategy in the powertrain control module (PCM).

The IPR is a pulse-width modulated valve operating at 400 Hz. The pulse width is modulated from a duty cycle of 8 to 50% to control injection control pressure from 3.4-20.7 MPa (500-3000 psi). The IPR is mounted in the high pressure pump and achieves injection control pressure regulation by discharging excess oil through a shuttle valve into the front cover and back to sump.

The PCM controls the injection pressure regulator (IPR) by an internal ground switch (low side driver) internal to the PCM. Pressure control is a variable function of the engine control strategy and the calibration that has been programmed into the PCM.

The injection control pressure (ICP) sensor is mounted on the left cylinder head and is the feedback signal for the closed loop control system. The ICP sensor is a ceramic disk-type pressure sensor that converts pressure into a 0 to 5 volt analog signal that the PCM uses to determine injection control pressure. Typical operating range is 0.7 to 3.2 volts.

A spring/piston pop-off valve is installed internal to the high pressure pump and is set to discharge oil pressure into the front cover in the event injection control pressure exceeds 27.6 MPa (4000 psi).

Diagnostic stuff would take me too long to post, let me see if I can find a link (or maybe someone will beat me to it). Cheers!

 

[agomez]

Patrick based on some of the schematics I have seen the ipr shows a port that it cuts off to allow pressure to build so the injectors will fire.....my question is, the port that it is cutting off, does that oil drain back into the oil pan? thanks for the post I have come accross alot of info on the high pressure end and I'am in the process of trying to absorb it all.

 

[okney1lz]

Short answer, yes

It drains to the pan. Attached diagram shows basic operation. Hope this helps.

 

[Patrick Feeley]

Here's a link to the "IPR Diagnostics"

Here's some more description of the IPR taken from an International HEUI brochure that used to be around a long time ago. I changed the acronyms to the ones we use here. Sorry for the lack of the pictures that go with the description below!

The IPR is an electronically controlled pilot operated pressure control valve. The basic components of the IPR are the: Body, Spool Valve, Spool Spring, Poppet, Push Pin, Armature, Solenoid, and Edge Filter (later ones don’t have the edge filter).

The IPR controls HPOP outlet pressure in a range between 450 and 3,000 psi. An electrical signal to the solenoid creates a magnetic field which applies a variable force on the poppet to control pressure.

OPERATION – Engine Off

With the engine off, the valve spool is held to the right by the return spring and the drain ports are closed.

OPERATION – Engine Start Up

Approximately 1,500 psi of oil pressure is required to start a relatively warm engine. If the engine is cold (coolant temperature below 32F), 3,000 psi of oil pressure is commanded by the PCM.

Oil flow through the IPR is as follows: Pump outlet pressure (red) enters the end of the body and a small amount of oil flows into the spool chamber through the pilot stage filter screen and control orifice in the end of the spool. The electronic signal causes the solenoid to generate a magnetic field which pushes the armature to the right. The armature exerts a force on the push pin and poppet holding the poppet closed allowing spool chamber pressure to build. The combination of spool spring force and spool chamber pressure hold the spool to the right closing the drain ports. All oil is directed to the pressure rail until the desired pressure is reached.

OPERATION – Engine Running

Once the engine starts, the PCM sends a signal to the IPR to give the rail pressure desired. The injection control pressure sensor (ICP) monitors actual gallery pressure. The PCM compares the actual rail pressure to the desired rail pressure and adjusts the signal to the IPR to obtain the desired rail pressure.

The actual oil flow through the IPR during engine operation is as follows: Pump outlet pressure (red) enters the end of the body and a small amount of oil flows into the spool chamber (orange) through the pilot stage filter and the control orifice in the spool. The pressure in the spool chamber is controlled by adjusting the position on the poppet and allowing it to bleed off some of the oil in the spool chamber. The position on the poppet is controlled by the strength of the magnetic field produced from the electrical signal from the PCM. The spool responds to pressure changes in the spool chamber (left side of the spool) by changing positions to maintain a force balance between the right and left side of the spool. The spool position determines how much area of the drain ports are open. The drain port open area directly affects how much oil is bled off from the pump outlet and directly affects rail pressure. The process of responding to pressure changes on either side of the spool occurs so rapidly that the spool is held in a partially open position and pump outlet pressure is closely controlled. The IPR allows infinitely variable control of pump outlet pressure between 450 psi and 3,000 psi.


Hope this all helps! Cheers!

 

[[email protected]]

but where does the ipr sit any pics would be great im working on my 04 hpop problem and in a box of parts that the dealer put on my back seat is my ipr (gathered it was ipr from a pic on ebay).

 

[agomez]

sgt your in the 94-97 section not sure on your 04....Patrick thanks for the info you are really good at tracking info down...when I first found this site years ago the search function was ten times better than it is now it is very vague...it seems as though alot of good info got lost in the change.....anyway thanks again...

Andy


okney thats what I thought when i get my truck warm turn it off I have to refill the resivoir to get the truck restarted I can here oil dripping down what seems to be the front of the oil pan and air bubbling up...this leads me to believe the ipr is not functioning properly...

 

[meissler]

Here's a link to the "IPR Diagnostics"

Here's some more description of the IPR taken from an International HEUI brochure that used to be around a long time ago. I changed the acronyms to the ones we use here. Sorry for the lack of the pictures that go with the description below!

The IPR is an electronically controlled pilot operated pressure control valve. The basic components of the IPR are the: Body, Spool Valve, Spool Spring, Poppet, Push Pin, Armature, Solenoid, and Edge Filter (later ones don’t have the edge filter).

The IPR controls HPOP outlet pressure in a range between 450 and 3,000 psi. An electrical signal to the solenoid creates a magnetic field which applies a variable force on the poppet to control pressure.

OPERATION – Engine Off

With the engine off, the valve spool is held to the right by the return spring and the drain ports are closed.

OPERATION – Engine Start Up

Approximately 1,500 psi of oil pressure is required to start a relatively warm engine. If the engine is cold (coolant temperature below 32F), 3,000 psi of oil pressure is commanded by the PCM.

Oil flow through the IPR is as follows: Pump outlet pressure (red) enters the end of the body and a small amount of oil flows into the spool chamber through the pilot stage filter screen and control orifice in the end of the spool. The electronic signal causes the solenoid to generate a magnetic field which pushes the armature to the right. The armature exerts a force on the push pin and poppet holding the poppet closed allowing spool chamber pressure to build. The combination of spool spring force and spool chamber pressure hold the spool to the right closing the drain ports. All oil is directed to the pressure rail until the desired pressure is reached.

OPERATION – Engine Running

Once the engine starts, the PCM sends a signal to the IPR to give the rail pressure desired. The injection control pressure sensor (ICP) monitors actual gallery pressure. The PCM compares the actual rail pressure to the desired rail pressure and adjusts the signal to the IPR to obtain the desired rail pressure.

The actual oil flow through the IPR during engine operation is as follows: Pump outlet pressure (red) enters the end of the body and a small amount of oil flows into the spool chamber (orange) through the pilot stage filter and the control orifice in the spool. The pressure in the spool chamber is controlled by adjusting the position on the poppet and allowing it to bleed off some of the oil in the spool chamber. The position on the poppet is controlled by the strength of the magnetic field produced from the electrical signal from the PCM. The spool responds to pressure changes in the spool chamber (left side of the spool) by changing positions to maintain a force balance between the right and left side of the spool. The spool position determines how much area of the drain ports are open. The drain port open area directly affects how much oil is bled off from the pump outlet and directly affects rail pressure. The process of responding to pressure changes on either side of the spool occurs so rapidly that the spool is held in a partially open position and pump outlet pressure is closely controlled. The IPR allows infinitely variable control of pump outlet pressure between 450 psi and 3,000 psi.


Hope this all helps! Cheers!

Patrick,

I see you are well versed in the Ford 7.3 IPR. If I may I would like to pose a question. Inside the IPR is a bullet shaped component with grooves machined around it's circumference. Inside that spool? valve is a component with a flat groove machined on the end. The flat groove is both visible and accessible from the side of the spool valve with a small flat bladed screwdriver. I turned that part counter clockwise somewhat before I realized I was altering a factory setting I should be leaving alone. Do you know what turning that component located within the spool valve does and what measurement I need to take with the engine running to determine if I need to try to readjust that component back to factory spec.? Any wisdom you can impart would be greatly appreciated. Thank you.

Steve Meissler