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Hpop issue?

3K views 16 replies 3 participants last post by  klhansen 
#1 ·
This morning I started my truck 38 degrees not plugged in. The injector pressure was reading 845 psi at idle. I drove my usual route to the freeway. But when I got on the throttle to get up to speed on the freeway it started to shut off and re fire and I barley got to the exit when the truck shut off. So I pulled of to the side. I tried to restart and the injector pressure on my edge monitor only went to 245 psi. The code is 1211. I got towed to my storage unit and change the icp and the ipr both are new and the pressure went up to 273 So I am wondering if this is a hpop failure. I change my oil every 5000 miles I have 260,000 on the clock. Thank you, Jeremy
 
#2 ·
More likely injector o-ring leaks than a HPOP failure. HPOPs don't go bad very often.
Could be as simple as low oil level. Check the dipstick before doing anything else. Then check for leaks at the HP oil hoses to the heads. Then maybe do a HP hose block-off test to see whether the injector o-rings are leaking. If it starts with one hose blocked off, then you have leaks on the head that's blocked off. If you find any that are leaking, go ahead and replace the o-rings on all the injectors.
 
#4 ·
So when you blocked off he HPOP hoses and got low pressure readings, how were you checking the pressure. With the ICP sensor, you can get readings on the driver's side head with the passenger side blocked off, but when blocking off the driver's side hose, you need to install the ICP sensor on the end of the hose with an adapter to be able to read pressure. If you had the passenger side blocked off and got 273 psi on the driver side head, then I'd say you have leaks in the driver's side that are preventing the HP oil pressure from getting to the required 500 psi for starting.
I'd reply here instead of by PM to me, so everyone has benefit of your tests and can weigh in on a solution for you.
 
#5 ·
I blocked off the drive's side first and had a reading of 273 psi. I had forgotten to block the oil rail crossover hose I have. So I blocked off the crossover hose and I re-tried the driver's side again had a reading of 273 psi according to my edge monitor. I then re installed the driver's side hose and blocked the passenger side and the pressure was 273 psi. With no start on with either side blocked off. So I had a paper I printed off from all data that said to if no start to block off both hp hose and if the pressure is under 1000 psi to check the ipr o-rings. I had looked at the o- rings before I put in the new ipr they looked good. I then blocked both hp lines cranked the engine and the monitor showed 0 psi.
 
#6 · (Edited)
Again, how were you measuring pressure?

I don't understand how you got pressure if the crossover line to the open driver's side head was still connected (unless you also blocked the hose port in the head.) Normally, the blocked off head would be at atmospheric pressure (0 psi gauge).
Here's a good resource for diagnosing HPOP issues. It includes instructions for the hose block-off tests.
https://www.thedieselstop.com/faq/9497faq/download/HighPressurePumpSupplementDiagnostics.pdf
 
#7 ·
I was using the (edge monitor) that plugs into the obd port to read pressure from multiple sensors icp, ipr, fuel, rpm egt's oil temperature ect. The crossover line is blocked. So today I bought a 3000 psi pressure gauge. Tonight after work I hooked the gauge up to the driver's side hp line and the pressure reading went to 300 psi and stopped. Now I am assuming with the hpop lines blocked off it would make 2500 to 3000 psi when cranked since the pressure has nowhere to go.
 
#8 ·
Tonight after work I hooked the gauge up to the driver's side hp line and the pressure reading went to 300 psi and stopped.
That would tell me that there's leakage in the passenger side head (the one with the line connected to it). Blocking both lines should give you much higher pressure. At this point (until you block both lines and get a reading), I think you're looking at replacing injector o-rings. I think I mentioned that you should do ALL the injectors.
 
#11 · (Edited)
Fuel pressure wouldn't affect a full block-off test, as the injectors (and fuel system) are isolated from the HP oil system. But it might be an issue when blocking off one head.
Jeremy, can you describe EXACTLY the setup you are using in each of the block off tests? That way we can help you diagnose it correctly. If you have both hoses blocked off (one with a gauge on the end of it), then your issue is with either the HPOP or IPR. The only way then to tell which is to install a known good IPR and redo the test. If you still don't get pressure, then the HPOP is not putting out like it should. I would check the torque on the bolt holding the HPOP gear on. It's accessible behind the diamond shaped plate on the front cover. It needs to be 95 lb-ft.

One other item. You need to verify that you're getting power to the IPR coil, and that the signal from the PCM (a pulsed ground) is working. As an alternative, you can connect the IPR connector to the battery (for a short time to avoid burning out the coil), which will fully close it and make the HPOP go to full pressure.
 
#12 ·
On the block off tests that I have conducted. I blocked all lines and connections and the crossover line with plugs and caps except of course the side I was testing using the pressure gauge. So today I finally was able to get my laptop fixed so I could use my autoenginuity program. So I went to the live graph screen an picked the icp pressure, duty cycle, and rpms. The duty cycle 14.8 I started cranking and the ipr duty cycle went to 64.89 with ipr pressure at 0, rpms at 175. I then went out and unplugged the icp and cranked again ipr duty cycle 64.89, pressure at 2370, rpm 170. So I tried to start the truck with the icp still unplugged with the driver side blocked off with the pressure gauge on it and the passenger side plugged off and had a no start and the pressure gauge barely moved, but the autoenginuity read 2370 psi. I then re-attached the passenger side and tried to start the truck and had a no start. I checked the torque of the hpop gear bolt and the torque wrench clicked at 95. Since I do not have a spare pigtail for the ipr I will have to take the ipr's to the local diesel shop and have them tested to make sure they are good or bad.
 
#13 ·
With that, it seems that you might have suffered a rare HPOP failure.
But you do need to get your IPRs checked to be sure.
 
#14 ·
I will get the ipr checked. I also remembered something else today while thinking about this situation their were times when the truck was fully up to operating temperature that I would go full throttle and the engine would cut out to idle until I let off the throttle pedal fully then I could get on it again and I could go full throttle but not fast. And sometimes I could go full throttle fast with no problem. I thought it was possibly a electronic problem with the the throttle pedal. So I just payed more attention to it but looking back on it now I think it is more than that. Does this sound like something was not keeping up with the full throttle demand?
 
#15 ·
The accelerator pedal (throttle is a misnomer on a diesel as there's no throttle involved :winking:) is a potentiometer. A coil of wire and a wiper, and they can go bad. Maybe the wiper spring is getting weak and contact is being lost. The PCM can't tell between an idle signal and an open circuit. You can check it with a multimeter, checking for a smooth change in resistance across the contacts as you move the pedal.
 
#16 ·
I beleive I have found the problem. I was disconnecting the wiring harness on the driver's side to remove the valve cover to re-shim the injectors and when I moved the harness the wire loom slid down from the connector on the ipr and both wires are bare and shorting out on each other. I did not see it because the open side of the loom was facing away from me and I did not see the bare wires. I guess I will have to look alot closer next time. Thank you for your help.
 
#17 ·
You're very welcome.
And thanks for closing the loop on this. (y) A short in the IPR wires would prevent any HP oil pressure buildup.
 
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