2009 UD2300 with the J08E engine. Loss of power

JoshuaL

New Recruit
Mechanic
Offline
Hello guys! Hope everyone is doing well.
I am working on a 2009 UD2300 with a Hino J08E engine. I'm hoping some of the Hino experts can help me out here. The truck is dealing with a loss of power. The issue has been happening for a few months now. The truck was taken to a shop that scanned it and basically deemed there was at least 1 injector that needed to be replaced but suggested we change all 6 of them. We purchased 6 non brand injectors and had them installed. For awhile the issue had been resolved but after a couple months its back to barely being able to climb hills unloaded.

The truck starts up with no issues, the fuel filter was replaced less than 3 months ago. We cracked the injector lines and 2 weren't getting any flow through the dampers. The common rail and all the flow damper were pulled and cleaned. There was some debris found in the common rail. Everything cleaned up nicely though, we put it back together and 2 of the dampers were still not flowing. We ordered 2 dampers and replaced them. I believe we had all 6 flowing if my memory serves me correctly. Took the truck on the road and same issue, no power.
I cracked all injector lines behind the flow dampeners and they were all spraying. I then cracked all 6 lines on the injectors themselves and only 5 were spraying. Going back I cracked the line by the dampener that was spraying earlier but it no longer sprayed any fuel. Then I double checked the 5 other injectors and another stopped spraying fuel. That makes 2 cylinders that weren't getting fuel. I cracked one more line, it sprayed and the truck shut off.
I tightened all the lines, pumped the hand prime on the filter and she fired back up, check the damper that stopped working and it started to spray again. What is going on? I'm curious if maybe there is air pressure getting trapped and perhaps there is a specific order of cracking the lines to get all the air out? Any input would be greatly appreciated!
 

Hino123

Expert Expediter
Researching
Offline
First off thanks for the good info and welcome. You don’t say what kind of debris was found in the common rail. Was it metal or dirt? We have seen fuel pump failures causing metal to lodge in the dampers. In almost 15 years of working on Hino’s I have replaced 2 maybe 3 flow dampers and they were all for external leakage. I don’t get too hung up on checking for fuel at all 6 injectors. I grab the fuel lines individually and check for. “Pulse” I then would perform a cylinder cut out followed by checking balance rates on each cylinder. Unfortunately for you I dowbt you have UD software. You say there was a code for an Injector, but don’t say if there are any codes or a CEL on currently. Just to throw some thing to check for now. It is plausible if you had debris in the rail that some of it got in the fuel pressure relief valve. In my experience if that valve opens it can get hung open if there is debris in the rail. Usually if it is faulty it will set a P0087 for low rail. pressure. A skewed MAF/IAT sensor could alter your fuel map and it lack power. Check the intake throttle valve butterfly and make sure it is tight & it should have 3 small holes drilled in it at the bottom. I have seen multiple issues with the common rail pressure sensor pigtail. I monitor it with software while wiggle testing it. Grab the pigtail and give it a wiggle with the engine running and see if it makes the engine sound different. I have seen lots of black balls of crap get stuck in the inlet banjo to the racor fuel filter housing. Might be worth taking them off an blowing them out. Is there any black soot in the tailpipe? What is the application, miles, hours on the unit. Sorry lots of questions and not many answers. Get back to me on the questions and hopefully I’ll have a little more to go by.
 
  • Like
Reactions: greasytshirt

JoshuaL

New Recruit
Mechanic
Offline
Hello and thank you for the quick reply and for your help.

So the debris in the common rail was dirt, I don't recall seeing any metal shavings.
You are correct, unfortunately I don't have any UD software or really any heavy duty scanners. I have a company near me that works on medium and heavy duty trucks. They are the people who scanned it the first time and advised we changed the injectors. There is a check engine light on currently which I have yet to scan.

I apologize for my incompetence but I am not sure I know where/what the pressure release valve looks like. Is it part of the return line on the common rail?

I did wiggle the plug on on the plug on the common rail sensor while the truck was running. No changes there (pictured below)
Pressure Plug.JPG

I also checked the mass air flow sensor and it seems to be clean. (Pictured below)
Mass Airflow Meter.JPG
I checked what looks to be the intake throttle valve butterfly (pictured below) and it moves/flaps freely. Perhaps you mean the throttle body that is supposed to be tight? Maybe the picture will give you an idea of what I checked.
Butterfly Flap.JPG
The tailpipe I have pictured, it did have soot when I gave it a swipe with my finger. But I think that's normal though for a diesel right?
The truck is a rollback, with 240k. We purchased it out of California and its clean truck all things considered.

Exhuast.JPGSoot.JPG
 

Hino123

Expert Expediter
Researching
Offline
Thanks for the detailed reply. The fuel pressure relief valve is on the lh side of the common rail to the lh of all the flow dampers. It has a 14mm banjo bolt in and connects the fuel return line. There is a bulletin to drill the 3 holes in the intake throttle valve. Give me your email and I can send you the procedure. The soot in the tailpipe indicates the filter is cracked and passing soot. I do not believe this is your current issue but we can revisit it later. Grab the shaft and wiggle it in the throttle valve. It should feel tight. If there is play side to side you will need to replace the throttle valve assembly. Unfortunately I think the key here is going to be getting the codes from the ecu. At this point I’m just guessing and providing checks that are able to be performed without a laptop. There is really no great way to check the MAF sensor. Best way it to replace it with a new one. They are the same as the Toyota pickups of that era. I got my test one from Amazon for $20. If you take the part number off the one you have and google it it should lead you to a replacement. The hino ones are like $200 from Hino but like I said you can get them for under $30. Greasytshirt may have some other ideas. Without and codes it gonna be a guessing game. The truck does look very clean tho. Should make a nice unit after you get this straightened out.
 

Hino123

Expert Expediter
Researching
Offline
Just another quick thought. I have seen those hand primers suck air in before. You could temporarily bypass the filter housing and see if the low power issue goes away. Make sure to use a genuine hino fuel filter as well.
 

JoshuaL

New Recruit
Mechanic
Offline
Okay, I bypassed the fuel filter and took it for a spin. No change unfortunately
I did what you mentioned about feeling the "pulse" on the injector lines. I feel a pulse in all the lines except for cylinder #4 which feels dead. I'm going to get one of the old fuel dampers and try swapping it out. Could it be that that injector went bad though?

ps. happy birthday!
 

JoshuaL

New Recruit
Mechanic
Offline
Just an update, I swapped the flow dampener out with both my old dampers. It did not make a difference. The line still feels dead to injector #4. Could this be a sign of faulty injector?
 

Hino123

Expert Expediter
Researching
Offline
Mmm hard to say. I don’t diagnose injectors that way. Anything is possible with aftermarket injectors. Did you program the balance rates when you replaced them? What brand of injectors are they? I am spoiled with OEM software. I would check the balance rate and do an injector cut out. On all the injectors. If you had a dead hold you would have a knock or a skip and some power loss. Hard to say without hearing it and being connected to it. Was the butterfly shaft tight? We could have a turbo issue, egr valve. It’s gonna be tough to diag without codes. I have UD software do you have a Nexiq USB link. Any chance you could bring it by that shop and just have them scan and print the codes?
 

ud2600bbs

Seasoned Expediter
Owner/Operator
Offline
Looks like the same issue i had with my UD do you get a check engine light? I use to have power loss and ended up being injectors fix that and a couple days later my HPFP went bad after that the truck works fine where are you located i have the ud software
 

JoshuaL

New Recruit
Mechanic
Offline
Howdy everyone. Still dealing with this issue unfortunately. I did have a shop scan it (just a typical diesel Snap-on scanner though.) There were no codes for the engine, just a minor transmission communication code. So back to the drawing board!
The mechanic at the shop thought that maybe there is a fuel return line in the motor that perhaps has a slight air leak. I'm not convinced but wanted to run that idea through you all.
One thing we did try was installing an in-line fuel pump by the fuel tank just to try to assist the fuel reaching the injection pump. It made no difference. I did pull the fuel rail and clean it again, it was completely clean. I'm running out of ideas unfortunately.
 

greasytshirt

Moderator
Staff member
Mechanic
Online
If the injector leak pipe is leaking, it'll fill the crankcase with fuel and then the engine runs away and explodes. That's the common failure mode with the return line.

If you still aren't getting flow through the dampers, I would try removing the damper's guts and reinstall. The later trucks don't even have dampers so I'm assuming that this is ok. If there's still no activity on #4 then Id have to assume the injector is not firing. Possible cause for that would be the wiring pigtail going to the injector. They can test good with a meter but fail to send the ~100 volts to the injector.

Troubleshooting these without sufficient software is an exercise in frustration.
 
Top