The 7.3 IPR valve — Injection Pressure Regulator sensor — works together with the high pressure oil pump to “create” oil pressure.
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7.3 IPR Basics
The 7.3 Powerstroke ICP — Injection Control Pressure sensor — sends the current pressure reading to the PCM — Powertrain Control Module — which in turn signals the 7.3 IPR to physically add or reduce pressure.
Ideally, the 7.3 IPR, ICP, PCM, and HPOP work together to provide enough oil pressure to the 7.3 injectors so that when you press on the accelerator, your injectors actuate and your diesel engine gets fuel and the cylinders fire.
7.3 IPR Location
So just where is the IPR valve located on a 7.3 Powerstroke anyway?
IPR Valve 7.3 Location
Your 7.3 Powerstroke’s IPR is located in the center of the engine compartment, screwed into the lower right rear of your high pressure oil pump—HPOP. And the 7.3 HPOP is located under the fuel filter housing.
7.3 IPR – Injection Pressure Regulator Parts
Here’s a detailed diagram of all the parts on a 7.3 Injection pressure regulator.
7.3 IPR Tinnerman (Tin) Nut
Is a thin sheet metal retaining nut designed to hold the 7.3 Injection Pressure Regulator solenoid in Place. The Tinnerman, or “tin nut” as it’s commonly called, is a 1/2″ x 20 fine threaded nut.
7.3 IPR Spacer
Allows the IPR to have its required length. Holds the solenoid in place.
7.3 IPR to HPOP o-ring
When the IPR is screwed into the HPOP this forms the seal between the 7.3 IPR and the 7.3 HPOP. NOTE: This is a 7.3 Common Leak Location and one of the first places to check if your 7.3 HPOP is leaking.
7.3 IPR Valve o-ring
Seals the IPR valve body to the oil channel, holding the pressure in the HPOP.
7.3 IPR Backup Split o-ring
Helps Seal in IPR valve body created HPOP oil pressure.
7.3 IPR Valve Function
In short, the 7.3 Powerstroke Injection Pressure Regulator controls the high-pressure oil pump’s outlet pressure. It’s a valve that interprets electrical signals from the PCM and turns them into actual physical hydraulic pressure in the 7.3 diesel’s high-pressure HEUI oil system.
This then operates the fuel injectors. The amount of pressure is controlled by the ICP – Injection Control Pressure sensor and the PCM – Powertrain Control Module – varying ICP pressure by adjusting the IPR duty cycle—add pressure or dump pressure.
So, even simpler… And believe me I’ve had a tough time understanding it until I boiled it down for myself:
- 7.3 ICP – Injection Control Pressure SENSOR (measures oil pressure)
- PCM – Powertrain CONTROL Module (send voltage signals to control what’s going on)
- IPR – Injection Pressure REGULATOR (valve that plunges to physically create (regulate) pressure)
7.3 IPR Symptoms
Common symptoms of a bad 7.3 Powerstroke IPR
- Poor, rough, or unstable Idle, especially when you let off the accelerator
- Injectors surging when you accelerate
- Stalling out
- Crank no start
- Loss of overall power
More 7.3 bad IPR symptoms:
- Random surging due to low power to the IPR
- Long crank/start times – hard start when the engine’s hot
Careful though, many 7.3 Powerstroke IPR symptoms cause the same bad behavior in your diesel as a failing ICP, a leaking 7.3 HPOP, bad valve cover harnesses and even a bad IPR or ICP pigtail.
Some specific 7.3 bad IPR symptoms
Your 7.3’s IPR may be stuck
Your 7.3 diesel will start sometimes and not others. When your truck does start, you’ll be able to rev the engine and then idle okay for a few minutes. Then your 7.3 diesel engine will start idling roughly and then it’ll shut off with no warning.
Your 7.3 Powerstroke won’t sputter to a stop, it’ll just shut down and won’t start again unless you apply a lot of throttle. Once your engine does restart, it’ll run and then idle until it shuts down.
Your 7.3’s Tin nut may have come loose
Yet another specific symptom is a result of the Tinnerman nut coming loose. If that happens the spacer and 7.3 IPR Solenoid will come off and your diesel engine will die.
7.3 IPR Test
If your 7.3 Powerstroke engine has any of the above-mentioned symptoms, you’ll need a way to troubleshoot it.
Obviously, a visual inspection of the 7.3 IPR where it screws into the HPOP would be in order. Check to make sure no oil is seeping from around the IPR, signaling that your 7.3’s IPR o-ring may have failed.
If you have a basic scan tool that will check the ICP pressure when you are starting your engine, make sure it generates the minimum pressure—500psi. If not, your problem may be in your high pressure oil system.
You can also remove the HPOP Reservoir inspection plug/fill port (scroll down to step #9 on that article) and check the oil level. If the oil is close to the top, the problem could be a bad or failing 7.3 IPR.
7.3L IPR Air Test
There’s a handy tool you can use to check if your 7.3 IPR is bad or if it’s another component in your 7.3 HPOP or high pressure oil delivery system. However, it’s geared more toward professional mechanics than us driveway guys and by the time you pay for it, you could get a new IPR and test to see if it was the culprit.
Remove the ICP Connector
When there’s no signal from your 7.3 ICP the PCM will use a default signal. So if you’re experiencing rough idle or no start conditions, try unplugging the ICP sensor harness.
If your diesel engine starts and/or the idle gets better, your problem’s most likely a bad ICP sensor not your 7.3 IPR valve.
7.3 IPR Removal
Tools you’ll for 7.3 Powerstroke IPR removal
1 1/8″ or 29mm extended deep well socket (a standard 3″ extended won’t clear the end of the IPR valve)
7.3 IPR Removal Procedure
- Disconnect both of your negative battery cables
- Remove the 7.3 HPOP reservoir inspection plug. The plug takes a 3/16″ Allen wrench (hex wrench).
- Use a fluid transfer pump (AMAZON LINK) suitable for fuel and oil to pump out the HPOP reservoir oil.
- Remove the electrical connector to the 7.3 IPR. It has a small wire bail securing it.
- Remove the IPR Tinnerman nut (little retainer nut on end of the IPR). You can use a 19mm socket on it.
- Remove the IPR Spacer – With the Tinnerman nut off, the spacer sleeve slides off easily.
- Slide off the 7.3 IPR Solenoid.
- Remove the 7.3 IPR from the HPOP with a 1 1/8″ extra deep well socket.
7.3 IPR Replacement
After you reseal or rebuild your 7.3 IPR, you’ll want to reverse the above procedure to put it back into your HPOP.
- Torque the IPR down to the HPOP – 7.3 IPR Torque spec – 35 – 37 lb/ft with a 1 1/8″ or 29mm deep well socket.
- Then slide the IPR solenoid and brass spacer back over the shaft.
- Then reinstall the Tinnerman nut. 7.3 IPR Tinnerman nut torque spec – 49 – 53 INCH lbs. (Don’t over tighten and strip it)
7.3 IPR Rebuild
7.3 IPR Rebuild Kit
A 7.3 IPR rebuild kit is pretty simple. You get a new:
- Tinnerman nut
- IPR spacer
- Small O-rings to reseal the 7.3 IPR valve itself
- As well as a larger o-ring to reseal the IPR to the HPOP.
Here’s the one I used from Amazon – 7.3 IPR rebuild kit.
Don’t forget to check out the IPR rebuild video below…
7.3 IPR Rebuild Video
Pay particular attention to the direction of the tiny pin at timecode 7:56 – The small end of the pin should point toward the HPOP in reassembly.
7.3 IPR Pigtail
Technically it’s called a 7.3 IPR VGT Solenoid Connector Pigtail. And it’s a 2-prong electrical connector with a wire retaining bail to keep it secured to the IPR connector.
7.3 IPR Pigtail Part Number
7.3 IPR Part Number
IPR 7.3 Part Numbers by Model Year:
Year: 1998.5-2003.5 – Engine Serial Numbers: 661,496 to 2,030,402
Year: 1996-1998.5 – Engine Serial Numbers: 187,100 to 661,495
Year: 1994-1996 – Engine Serial Numbers: 501 to 187,099
7.3 IPR Torque Value
IPR – 47 Nm (35 – 37 lb/ft)
IPR Solenoid Tinnerman Nut – 6 Nm (53 lb/in)
7.3 IPR Summary
And there you have it. Your 7.3 injection pressure regulator’s an integral component of your 7.3’s HEUI — hydraulically activated, electronically controlled, unit injector — fuel delivery system. Take care of it and you’ll have smooth running and plenty of reliability.