Maxxforce DT Higher Than Desired ICP

Zachary Mobile Technician Austin, Texas Posted   Latest   Edited  
Question
Driveability
Heavy Duty
2012 International 4300LP 7.6L (MaxxForce DT)
Injection Control Pressure Above Desired

VIN:1HTMMAAM3CH436007

Good afternoon all and thank you for your time. I've posted a couple different things about this truck but it has yet another issue (surprise!) Customer complaint was long crank/hard start when the engine is warm. I suspected a leak in the high pressure oil system so I scanned it for codes & retrieved a 164-1 for ICP unable to build during cranking. I got the engine warm & confirmed the complaint while monitoring ICP on the scanner. Suspecting a high pressure oil system leak, I obtained the necessary fittings to air check the system. When I performed testing prior to replacement of the parts, I set things up so I could have a gauge inline with the hose from pump to cylinder head & a shut off valve as well. My thought was once the crank no start occurred, I could use the shut off valve to quickly dead head test the pump & then break in to the rail side of the system & air check while the engine was good and hot. The ICP was higher than desired with this set up installed by roughly 400-500 psi. At the time, I was attributing this to the manner in which the test hose & fittings were installed. It moved closer to desired when the idle speed was raised. With air pressure applied, I was getting a lot of noise from the oil rail. I used a stethoscope to determine the worst of it coming from Cylinders 2 & 4 with leakage at 1 & 5 as well. Long story short, the tops of the injectors where the adapters connect were worn & causing the leakage. When I attempted the dead head test to check pump condition, the cranking sounded slow and I stopped immediately. I didn't think this would cause a problem as the factory manual calls for a dead head test but didn't want to push my luck. The #3 injector was replaced last year & given the mileage & difficulty to reach these, I suggested replacing the remaining 5 with new injector adapters. Replaced all the components & reassembled enough to start the engine. Truck starts & runs but now I have approximately 1500 psi of ICP at idle when desired is more like 870. Code 164-16 sets for ICP pressure above desired level. It fires right up on a hot restart so I'm confident that part is fixed. I can unplug the IPR and the system will build about 300 psi while cranking. I removed the ICP & installed a gauge just to back that reading up. If I start it with the gauge in, the pressure is something like 3200 psi at idle. I removed the ipr to see if anything was stuck in it and didn't notice anything off. I then sprayed some brake clean in while manually operating the plunger & reinstalled with no change. I'm assuming at this point I damaged the IPR & need to replace it to correct this problem. I wouldn't think an internal issue with the pump could cause this since the IPR is what controls the pressure. I'm reasonably familiar with the HEUI system thanks to Ford but this truck is the only MaxxForce DT I've ever worked on. Whatever the case I want to make this right and learn from my mistake. I'd also like to be sure I'm not missing anything before I eat the cost an IPR valve for this truck. Any input here is greatly appreciated. Thanks for making it to the end, hope everyone is doing well. 

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

When you checked icp with agauge. Did you still have icp sensor tee'd in and compared. The icp sensor could be biased a little high. Here should be diag manual for your emissions/engine. drive​.​google​.​com/file/d/16dwUjc…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Hi Jess, Thanks for your response. No the ICP sensor was removed. I didn't have the correct fittings to have the sensor & gauge in at the same time. The cranking reading on the gauge matched the sensor reading. The ICP voltage was about .25 Volt KOEO which is what I'm used to seeing on the 7.3 & 6.0 Powerstroke engines . I assumed that was correct for these too being that they're all…

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

The cranking pressure, seems about right without ipr hooked up. With running 1500 actual vs 800desired and assuming ICP is good. The ipr most likely has debris or mechanical issue. The only other thing would be a external grounding of Ipr wire. Increasing duty cycle of solenoid and pressure. The Ipr doesn't really have any checks of the circuit by ecm. It is normal powered by fuse and grounded…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Jess thanks for the information. I'd never watched pressure on cranking with the IPR unplugged so I couldn't be sure if this was typical. That diagnostic manual is way more current & comprehensive than the version I have for this engine. I'll do some more testing & get back with you.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Jess, Looking through the diagnostic manual you provided I saw mention of doing a fuel system reset following h.p.o. repairs. The scanner I'm borrowing for this doesn't offer that feature but I'm wondering it that could potentially be all it needs. I'm not seeing the ECM pull back on the IPR duty cycle to try and bring the pressure down. I'd have thought it would be attempting to make more of a…

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

Zachery, you might have a pump problem. If you full field the IPR by unhooking it from the engine harness then applying direct Vbat power and ground (no more than 60 seconds) what PSI do you get? These are the ranges. Your in the last group. It is OK to let it start and run for a few seconds. It will sound very weird. I would try full field first. Then pull the IPR and put in a blockoff tool…

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

I have deadheaded pumps also to confirm max pressure. Main issue is having a gauge high enough. I made a harness based off of a old IH troubleshooting bulletin that is no longer up. There is a fitting that will screw into the head end of HPOP hose. You use a spare ICP sensor in fitting. With harness you actually use map sensor connector(ecm side) to power and read voltage output of sensor. So…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Rex thank you for all the great information. I'm going to do that additional testing and follow up with the results. I take it you mean pressure reading per the ICP sensor? Or are you Teeing in a gauge for comparison? I always appreciate a long rambling old guy story. Lots of wisdom in those. :) The oil was sampled awhile back on this engine & showed high wear metal content. The lab's…

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

First thing. Find out what the aluminum content was on that oil sample. The EPA 2010 and up engines (twin turbo) have a bad problem that was never directly addressed. Short story is aluminum starts to "flake" off the three intake pieces. The actual intake manifold, the air mixing box that holds the EGR valve and the crossover tube from the EGR cooler to the intake manifold. This puts aluminum…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Rex thank you again for all the excellent information. The sample for this engine came back as 407 ppm of aluminum which I realize is through the roof. High iron content as well which is never good. I knew about the open breather conversion because you were gracious enough to share that information on a previous post I had for this truck. The customer requested the open breather conversion be…

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Kevin Owner/Technician
Litchfield Park, Arizona
Kevin Default
 

Zachary, Rex and others have given you some great info. With the aluminum content, I might at a minimum replace the intake and crossover pipe. This should slow down the manufacturing of aluminum. You might plan on an EGR valve, As you might not get it out. I would still consider it a Band-Aid, A proper overhaul would be the correct repair. This should have the updated IPR (straight…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Kevin you're absolutely right. Everyone who's responded to this post has been incredibly gracious and forthcoming with information...Yourself included. I'll mention the prospect of replacing the intake pieces to the customer but I 100% agree that it's a band-aid. To that point, suggesting it makes me a bit uneasy. Based on our conversation yesterday, I'm not entirely sure what the future of this…

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

Jesse, neat use of google docs. I need to look into that. There are time I want to post info but the attachment gets taken down. ooks like with your approach they would have to delete the link out of your post.

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

The file was around 68mb if i recall. I Couldn't recall Diag's attachment guidlines. Some other sites. What you do, is attach a text file with the link inside. That way non members cannot download without being a member. Also separating site from possible viruses. Or if the legality of item is suspect (I.E. engine software)

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Matthew Mobile Technician
Bartlett, Illinois
Matthew Default
 

Sounds like a possible IPR issue to me as well. Make sure you get the updated pigtail with it, I think that is the only way the dealer is selling it now anyways.

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Matthew Mobile Technician
Bartlett, Illinois
Matthew Default
 

Also, it may not apply here, but what injector seals did you replace? I have also had issues with the injectors leaking at the rail, pretty common. Also common for them to return too much oil, you can sometimes see it with the valve cover off and cranking the engine. The pucks commonly cause leaks on these too though, I have started to replace the entire puck whenever I do an injector now. They…

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Matthew, Thanks so much for both of your responses. The injector pucks you mentioned are the seals I'm referring to. I initially thought that was the location of the leaking air but saw the worn tops of the injectors after the fact. I didn't think/know to check for that on these initially but found it before anything was too far reassembled. Since doing those & the injectors the hard start…

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

There is a seal kit, 1842626C96 for the pucks. Has enough to do all six. BUT it is not complete. There is an o ring and a wave washer that is not in the kit. Those are between the nipple and the base. Nipple is held in by a snap ring. There is a service note saying to use only on the EPA 2010 and up. Those would be the twin turbo engines. There have been about 10 part # changes on the pucks…

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

I know our seal kit only includes for nipples and oring passage in head for manifold. We sell pucks. But yet to see individual parts for pucks. If you see any fretting of puck or injector cavity. It is certain truck will be back without new pucks. Nipple seals will not last. Had issue with reman injectors in past being sold with fretting also on reused parts.

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
   

I have seen the fretting. We always use new pucks unless, as I said, we have to go back in on an engine where we know the pucks are current. Some thoughts on injectors. We only use Pure Power injectors. They are sold thru Alliant. PP is the OE on that injector. They offer new and reman. I have only had a problem with one over the last few years. We put in maybe 20 sets a year. Don't know what…

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Jess Diagnostician
Windsor, Wisconsin
Jess Default
 

Yeah Zach used to work in FIE, Mara is stationed near service writers/manager. I am in service dept. You probably know more history on the injectors then alot of people.

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

Small world. Tell them I said hi.

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Zachary Mobile Technician
Austin, Texas
Zachary Update
 

Just wanted to take a moment to update everyone on the situation. Based on the excellent information provided by everyone whose responded, the cause of the high ICP has been traced to an internal fault within the pump. The customer wants to get rid of the truck because of the issues he's had and the knowledge of the impending engine overhaul. I believe he's going to have me replace the pump…

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

Glad you updated. The attachment should help you get some adapters for future adventures. They are Parker parts #'s

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Thanks Rex. I appreciate the wealth of information you provided on this one. In your experience, what's a typical IPR percentage on these engines at idle? Seems like 25-35% was typical on the 7.3/6.0 applications but it's been a bit since I've worked on one.

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Zachary Mobile Technician
Austin, Texas
Zachary Delay
 

Hadn't yet posted the ultimate resolution as I've been waiting on the pump to come in. Finally showed up and I should be back out there Monday to make the final repair. I'll update the post accordingly once this happens. Thanks for your patience.

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Zachary Mobile Technician
Austin, Texas
Zachary Resolution
 

Well it's finally over. The truck is fixed and I have some important information to share with the group. I was all set to replace the pump on this truck. I had the old unit off and the new one ready to install. However, there was something about the way this problem showed up and the IPR duty cycle at idle wasn't sitting right with me. I'd called the Alliant Power tech line to ask a question…

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Rex Technical Support Specialist
Alliance, Ohio
Rex Default
 

Zachery, good job. I didn't reply to your last question on percentages. Sounded high but there is not a published spec (that I can find) on the newer engines. Meant to look at some snapshots, never got to it. Having a problem of my own I may throw up on here.

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Zachary Mobile Technician
Austin, Texas
Zachary Default
 

Hey Rex no problem at all. You spent a lot of time posting valuable information and I really appreciate it. I thought it seemed high too based on other HEUI applications but as you said there's no spec. If you do decide to post, I'll help you anyway I can. Thanks again!

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