Diesel RV Club, an FMCA Chapter

Technical => Fuel System => Topic started by: seeing the sights on December 30, 2017, 12:37:32 PM

Title: HEUI Pump
Post by: seeing the sights on December 30, 2017, 12:37:32 PM
  If someone could give me their opinion. Started our trip in Pa very cold when we left.  (oil filter bypass on high pressure?) drove 350 miles no problem stopped for fuel started the 2006 C7 got back on highway engine derated itself, check engine light on. Pulled codes low fuel pressure. I then changed the 2 filters, same code and derate. towed to Triple T truck Warsaw NC. Technicion will look at it 1/2 Tuesday I belive it could be the HEUI pump. What can I do so I don't have this happen again?
I have read that if the oil pressure is to high (cold weather) the oil is bypassed around the filter causing dirty oil to drive the HEUI pump witch it turn causes the bearing to fail.   
If it turns out to be the pump What action do you recommend? 

1   Replace pump only
2   Replace Pump and all injectors kit # 20R0643
3   Replace Pump and all injectors also flush lines to injectors
4   Replace Pump and all injectors flush lines and add a filter that goes only to the HEUI Pump new CAT kit #20r6642
I will have the tech do a oil and filter change
Thanks Joe Brey 

Title: Re: HEUI Pump
Post by: Brett Wolfe on January 01, 2018, 05:51:43 AM

After reading your post, I got an e-mail from a retired Caterpillar Tech, Dave Atherton.  I am posting this with his permission:

Joe Brey, think is getting ready to spend lots
Of money. Reading post of problems with Cat -7 sounds like a story I have dealt with several times in past year.
First of all having a check valve sticking open would not in anyway take out the bearings in the heui pump. Second
No mention of any Cat ET diagnostic codes posted from technician troubleshooting problem. Third putting in
set on injectors in addition to install heui pump again there is no merit to change out a set of injectors. What Joe
Is looking at before getting out the door with the heui pump and set of injectors money wise $ 10,000. This drill
sounds like a script that I dealt with again several times. Going back to heui pump ( what does it do ? ) creates
Engine oil into high pressure oil from crankcase via: heui pump, the high pressure than enters oil rail by opening
What is called injection Actuation pressure Regulator and controlled by injection pressure sensor signal from
The engine ECM. Troubleshooting heui pump ( low oil pressure ) technician says heui pump bad, the only problem
With this high pressure cannot go to oil rail with out first going through the injection Actuation pressure regulator
( basic this is a valve that opens and closes ) valve operates via signal from engine ECM. The first place that will
cause low oil pressure is the injection Actuation pressure regulator not the heui pump. The location of the injection
Actuation pressure sensor for Cat C-7 in under the cover of the heui pump. The technician connect Cat ET doing
troubleshooting should supply you with ET Diagnostic codes present which I can show direction how to proceed.
The Cat ET codes holds the information on what failed or what has not failed. Again this post is to me script I have
heard before several times. Dave Atherton Retired Cat Mechanic
Title: Re: HEUI Pump
Post by: Brett Wolfe on January 01, 2018, 07:53:44 AM
More from Dave Atherton:

Hi Brett, looking over Joe Brey post again and problem is not within the injection pump as his technician and
Information there posting. This is not Engine oil pressure problem with heui pump but a diesel fuel related problem.
the derate of engine could be one injector firing off and on ( this is not saying injector is bad ) but electrical connection
to injector. What he has going on is a event code that should be logged on the ECM. If Ken will look up on the
BAC forum ( Ask Dave technical Area ) I have posted a very common problem on injector firing off and on with
Electrical connection to injector. The engine oil return to oil pan gets into loose electrical connector and kills the
contact. This problem is getting very common and a very easy and very low cost fix owner can preform. Dave

Tell me he really not understanding the problem fully and plans to throw parts at problem. Going deeper into his post which I should picked up onThis first but he wanted. Direction to what he posted of which I answered. This is a real good example on Joe
part not to get into a big hurry and start on repair. Dave

Think a person can understand problem and can find injector not firing by removing electrical connection.
Clean up oil on both injector socket and male end with brake clean, install two small o-rings over male end
reconnect electrical connection and zip tie metal holding clip in place to make tight connect.
Title: Re: HEUI Pump
Post by: seeing the sights on January 01, 2018, 10:38:34 AM
Thanks big time for your reply's,  The motorhome has not been seen by a tech yet. I am told it is in line for Thursday. All this talk about pump and injectors is just me looking online at worst case scenario  . After reading alot about this issue, first I will get codes. Then I was going  to have the tech replace the pressure reg.  Is the pressure reg. on the back side of engine and the pressure sensor is under the pump cover?  All I ask is that you 2 guys don't give up on me. I will keep you posted. I will be at the service center 7 AM tomorrow. to talk to service guy. I will ask him if he can pull codes and let you guys know what they are I DON"T want to spend more then necessary but how do you tell a tech what to do. Thanks, a TON   Joe Brey
Title: Re: HEUI Pump
Post by: Brett Wolfe on January 01, 2018, 01:32:15 PM
More from Dave:

Reading Joe post, the injection Actuation is located in the heui pump housing and opening a door expense.
My suggestions just have them Provide a complete Cat ET readout and print out codes, at this point have a time out
without anything else that would create out lay of more money. With Cat ET have them do an injector cut out
test if they will. Buy some time so you can check yourninjectors
Title: Re: HEUI Pump
Post by: Ken Carpenter on January 01, 2018, 02:04:18 PM
Here is some additional information from Dave on injector problems:

When troubleshooting an injector related problem, service shops often remove the electrical connection but fail to check the connection or inspect the rubber boot that was designed to protect the connection. Since the connector is in the injector socket it gets soaked in hot engine oil, leading to failure at some point.

In the heui injection system, excess engine oil returns back to oil pan from top of the rocker assembly. Over time the little sealing boot that seals engine oil out of electrical connection at injector breaks down. The boot is only about ¼ inch and simply protects the interface where the connector is mated with the socket. The hot engine oil at the electrical connection pins can kill the electrical power to the injector. This will generate diagnostic code 164-11 (Injector Actuation Pressure Fault) on your Silver Leaf or Aladdin.  (This fault may be intermittent due to the electrical connection making and breaking). Many shops will replace the injector since the code indicates a failed injector without ever checking the electrical connection.

Once the boot has failed, it cannot be re-used. The rubber boots cannot be bought without buying a wiring harness for injectors, which can get expensive. CAT does not supply the boots on current engines. There is an on-the-road repair that is fairly easy (and far less costly).

Remove the valve cover to access the injectors and electrical connectors at each injector. Disconnect the connector as shown in the first picture. Apply spray on brake cleaner to clean and dry the connectors, especially the pins and sockets. Next slide 2 small o-rings over the connector on the right (in first picture). This should result in a tight fit when the plug mates to the socket. The o-rings need to be tight enough to seal the gap. Then replace the metal clip and use zip ties (will break down over time) or mechanic’s wire (preferred) to hold the clip in place by connecting the tie/wire across the 2 loops of the clip on either side below the connector.

It is suggested that if one injector fails you apply this fix to all injectors at that time. The injectors themselves are designed to run 300000 miles without problems. This repair should cost you less than $10 in parts

Dave Atherton Retired Cat Mechanic
Title: Re: HEUI Pump
Post by: seeing the sights on January 01, 2018, 06:46:18 PM
Here we go, Tuesday AM I am going to pull valve cover off the C7, clean and put O-rings on my injector electrical plugs.
Will give an update. I want to thank Dave, Brett and Ken for all their help. I have learned over the years that most people are very kind and caring. The people that came to our aid reassures me of this, Thanks so much.  Cyndy and Joe Brey
Title: Re: HEUI Pump
Post by: seeing the sights on January 03, 2018, 05:15:04 PM
Sorry for not replying sooner,  but we were cruising down route 95 at 60 MPH with no check engine light, except for 3 short 1 minute  intervals,with no derate  last 400 miles and no check engine at all.  I believe I should have used 2 O-rings or 1 fatter one.  I am going to see what happens on the 1,000 mile ride home in 9 weeks. May redo the O-rings when we get home. I just want to thank Dave as his knowledge is invaluable. My conversations with Dave were very educational.

Just a side note, the motorhome was at the truck repair center. Tuesday morning I got there before they opened. I told the service manager that my wife said " we're not going to spend 1 more dollar on this motorhome and we are going to trade it in at the next RV dealer". I asked if I owed anything for storage and was told nothing was owed. Then I ran out of there with my wallet intact. 

Once again, Thanks to all involved. Brett, Ken and a BIG THANKS to the CAT KING  Dave Atherton
Title: Re: HEUI Pump (UPDATE)
Post by: seeing the sights on March 11, 2018, 05:17:05 PM
    Hello, All is well drove 1000 miles north with no issues. Breaking down was a big eye opener to me although I always thought I was up on all maintenance on the coach.I plan on going over it head to toe.

    My next project is to get the CAT ET codes pulled and hopefully I can find someone to interpret them. After that all filters and air dryer,coolant, belts and hoses re-do o-rings at injectors.

We have owed the 2006  motorhome since new and it desires a good going over.

Once again thanks to all that helped us with this. Big thanks to  Dave Atherton for all his help.

Dave if you are seeing this I might ask you to look at the CAT codes when pulled.

Thanks, Joe and Cyndy

Title: Re: HEUI Pump
Post by: David.e.atherton on March 12, 2018, 05:43:09 PM
Yes, I can give you the information you will need. One thing you can do is pull up
The blink codes off your cruise control and give that information to me also ( it is
called Caterpillar messenger ) Glad to hear you had a good trip after up and running.
Ask Dave, Dave Atherton Retired Cat Mechanic
Title: Re: HEUI Pump
Post by: fraydknot on August 14, 2018, 05:21:09 PM
Hi everyone, newly registered and first time posting. I just want to find out how this "O-ring" repair has held up. I recently started experiencing these identical symptoms. We traveled to Chicago from Jacksonville, Fl. and back without any issues back in April 2018. On Memorial day weekend we traveled to central Florida and I experienced the check engine light (CEL) and engine derate after I kicked off the cruise control to our final stop (last 3 miles). It occurred again on our return trip home, about the last 3 miles. We have since made a few more small trips with minimal occurrences. We attempted to make a trip to Disney World last week but had to change our reservations to a hotel since the light came on almost immediately so we chose not to push our luck, plus we had minimal power. Very frustrating!!! I have a CanDo code reader but the check engine light does not leave a hard code. During the occurrence I was able to drive with my reader plugged in so I got the following message: "PID94 Fuel supply pressure FMI1 Data valid but lower than operating range Activation 0". When the CEL is active the engine power is far less but there is no stored code which baffles me. This is why this post caught my eye. I am able to cancel cylinders with my reader and sometimes #2 & #4 cylinders do not make much of a difference when fuel supply is cut off and then all of a sudden this Cat purrs like a kitten. Also, on another note, I'm able to see at 700 rpm's my Injection Actuation Pressure is 2320.36 psi and the Desired Injection Actuation Pressure is 2320.0 psi. My injection actuation output is 43.50%.
This evening I removed the valve cover and unplugged each injector and at least 3 of the connections were covered in oil. I do not have the O-rings to install yet but I think I may have become a victim of this oil intrusion which would make sense why #2 & #4 cylinders are sometimes unaffected by the fuel cutoff.
What size are the O-rings that I should purchase?

Hopefully someone can help me. Before reading this post I was thinking the pump was going bad but if someone has seen the above said message from my code reader or has the experience to stop me before spending $3500 on a pump install then I would be forever in your debt.

Thanks in advance!
Title: Re: HEUI Pump
Post by: David.e.atherton on August 14, 2018, 07:01:24 PM
Hi Tim and welcome to the Diesel Club forum. The question asked about the Heui injection
system. The injector electrical connection in valve cover to injectors. First let me explain
some of the options a service shop is going to throw at you. The first approach you have
A bad injector or injectors and in most events will be injector number 5 or injector number 6,
than service shop will try to get you to install a complete set of injectors. Than approach
number 3 should change out your Heui pump. At this point you are looking at around $ 10,000.
Problem at hand for stopping at service shop low power. Why replace injectors ? They failed
engine cutout test with Cat ET Service tool. You already pin pointed where your problem
is located ( bad electrical connection to injector ) Caterpillar repair for this problem install
new wiring harness for injectors, cost wiring harness and labor around $ 5,000. Now the
question on repair with little o-ring the repair for doing all six injectors for supply’s is less
than $ 10.00 . Last answer to your question, does this repair work and how long does it last?
The answer to this question we have assisted many motorhomes and have not heard of
any problems and several have been out with this repair going on 3 or more years. We have
had several post reviews from motorhome owners and the Diesel Club has saved them over
Ten thousand dollars from service written quote for low power listed above. The Diesel
Club has a special area called Ask Dave, where technical caterpillar information is avaible
one on one to club members. The information is factual which can be backed up with hard
copy to member problem at large including part numbers and Caterpillar ET engine codes.
Again welcome To the Diesel Club from Ask Dave, Dave Atherton Retired Caterpillar Mechanic
Title: Re: HEUI Pump
Post by: antiqueclockservice on August 16, 2018, 07:38:15 AM
Hi Dave,

Any idea of when Cat started using the revised injector wire harness?  My C7 was assempled in 2004.

Title: Re: HEUI Pump
Post by: David.e.atherton on August 16, 2018, 06:30:06 PM
Phill, special instruction REHS1809, Installation Procedure for 156-7106 Injector
Wiring Harness kit.  Caterpillar engines included: 3126 A,  3126 B,  3126 E,  C-7
and C-9.  Media number SEBD-6763, date upgrade 01/ 12 / 2003.
Ask Dave,  Dave Atherton Retired Cat Mechanic
Title: Re: HEUI Pump
Post by: David.e.atherton on August 16, 2018, 07:33:13 PM
Phill, there is more to your question, last update 12 /23 / 2010 the following information
SEBD-6846. New injector wiring harness kit in now available to make injectors repairs
On 3126 A, 3126 B, 3126 E, C-7 and C-9.  New  366-9748 wiring harness kit replaces
The existing 156-7106 injector wiring harness.  There are no more technical bulletins
and new number for wiring harness 366-9748, because cost the o-ring on electrical connector
has not given any problems and easy to correct yourself at little cost to you.
Ask Dave,  Dave Atherton Retired Cat Mechanic
Title: Re: HEUI Pump
Post by: antiqueclockservice on August 17, 2018, 07:47:24 AM
Thanks Dave!
Title: Re: HEUI Pump
Post by: fraydknot on September 05, 2018, 03:02:07 PM
Hi again everyone, I recently replaced my HEUI pump, fuel pressure regulator and all filters. My issue now is my check engine light still comes on under a load but I now know what is causing it. The fuel pressure sensor is apparently bad. When I unplug the sensor, the engine performs flawlessly. Also, I get no check engine light informing me that it is unplugged either. I have a replacement sensor on order but my question is this, will it hurt for me to drive the coach with this sensor unplugged until I receive the new one and have it installed? Thanks for your help in advance! 
Title: Re: HEUI Pump
Post by: David.e.atherton on September 06, 2018, 05:44:02 AM
Tim, the fuel pressure regulator is a addon in area your talking about and will not do anything
If disconnected or removed and plugged. Ask Dave, Dave Atherton Retired Cat Mechanic
Title: Re: HEUI Pump
Post by: fraydknot on September 06, 2018, 12:08:54 PM
Outstanding!! Thanks Dave. I assumed it wouldn't but I just wanted to verify before we took off on our upcoming trip.

Title: Re: HEUI Pump
Post by: davidlquinn on August 22, 2019, 12:37:17 PM
I've been reading over this thread & trying to determine if it would work in my situation.  I have an 07 Phaeton with a 350 cat & I'm getting " Iva oil pressure sensor" code.  Cat replaced the sensor & it didn't help.  they tell me they think it's the heui pump but not 100% certain.  I've had different symptoms at different times.  a couple of times the engine would not reach over 1500 rpm wide open with the transmission in neutral.  If I put it in a gear it did not even have enough power to move the coach.  I could come back to it the next day & it would be perfect.  however most of the time it's fine but randomly & intermittently the check engine light would come on while driving & the engine would go into engine protect mode & only run about 45 mph.  is it possible that I need to do the above procedure to my injectors or should I replace the Heui pump?
Title: Re: HEUI Pump
Post by: David.e.atherton on August 23, 2019, 02:49:49 PM
David, this does not sound like Heui pump,failure, you indicated different codes on this
problem can you relate these codes numbers. You can help me very much if you can
share with me your engine serial number and the codes you indicated problems where
someone indicated Heui pump replacement. Ask Dave, Dave Atherton Retired Cat Mechanic
Title: Re: HEUI Pump
Post by: davidlquinn on August 27, 2019, 05:31:26 AM
Serial number

I don't know the exact code number but I do know that whatever the number, it's indicating a problem with the  "Iva oil pressure sensor —injector oil pressure for Huey pump".  (exact words they told me at Cat). It's the sensor on top of the engine at the rear of the coach, which I think would be the front of the engine, since it's reversed in the coach.  I was at Gregory Poole in NC & they decided the sensor was bad & replaced it but the issue continued.  Later I was at Ring Power in Orlando and they said they were getting the same code.  They determined the engine oil was dirty, changed it & put on a new air filter but the issue still continued.  The air filter had a hole in it causing unfiltered air to get into engine & the oil was getting dirty prematurely.  Even though this was definitely true, it did not solve the issue.
Title: Re: HEUI Pump
Post by: lewengel on September 02, 2019, 05:17:15 PM
Dave, Do I have A HEUI system?  Cat Serial 1WM21403

Thanks  Lew