2011 Hino 268, regen but no heat

Smith772 · Jul 10, 2017

I have a 2011 Hino 268 that will regen by pressing the manual button on the dash but no heat. It will regen for hours but the muffler isn't getting any hotter than normal. I have a dtc, P141F (burner malfunction). Tried a few things but don't really know what to look for. We removed the burner injector and it was pretty gunked up along with the igniters. Cleaned them and reinstalled and did a regen but all the same, loosened the lined that connects to the injector and its not getting any diesel during regen for some reason. Any thoughts, I'm new to Hino's and don't really know where to go from here. Any help is greatly appreciated.
Scott

greasytshirt · Jul 10, 2017

Hi Scott.

This system is going to be very difficult to diagnose without Hino DX software.

Think of this system like a big Reddy heater. There's an atomizer which mixes air and fuel, injecting it into the burner through the nozzle. There are two spark plugs. There's also a combustion air valve that allows air to flow in from the turbocharger outlet. Also throw in some temp sensors.

What's happening is that it'll attempt to light a flame, but it does not detect an increase in temperature, so it'll stop injecting fuel and the igniters will have spark sent to them to try to clean the tips off. After several minutes of that it'll try again.
Multiple things could be wrong. There could be a fault in the flame temp sensor. The combustion air valve could be stuck. The atomizer nozzle could be clogged. The mantle inside the burner could be broken.

How many miles does the truck have on it? If over 150k, replace the nozzle, both igniters, the flame temp sensor, the burner fuel filter, the crankcase breather filter. Take the big braided hose off of the front of the burner and clean out the passages very thoroughly.

You'll need the software to go any further. Also be very careful not to kink or twist the tiny braided line going to the nozzle, or you'll ruin it. The tips of the spark plugs need 2.5-3.5 mm gap.

greasytshirt · Jul 10, 2017

Also, P141F is a generic code sent from the burner control unit to the ECU, requesting the check engine light. The real codes are in the BCU, and I don't know of any software aside from Hino DX that will read them.

Hino123 · Jul 11, 2017

Welcome, since your newto Hinos I posted PM Schedule. Like greasytshirt mentioned the Nozzle, ignitors, and flame temp sensor should be replace at 150k. Also unless someone has reset it, there will be an annoying green indicator that comes on your meter at 150k asking for you to peform the "burner maintence"

Smith772 · Jul 11, 2017

Thanks for the quick responses, the truck has 220k miles and I just bought it so don't know if any of this stuff has been changed. I do have Hino DX but have no clue how to use it. I can plug it in and play with it if there are some readings that will tell a story and help troubleshoot or should a just chang the parts that you listed first? And thanks again to the both of you for the willingness to help others, I really want to learn more about these Hinos and I am looking at this as a learning opportunity. Just hope its not an expensive learning opp.....lol

greasytshirt · Jul 11, 2017

You have figured out how to connect to the ecu. How about the BCU? Are you using DX or dx2?

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greasytshirt · Jul 12, 2017

The first thing to do is to learn how to force a regen without using the DPR check function. If you force a regen through the engine ECU menu, you won't be able to watch the bcu.

Leave the ecu diagnostic menu and enter the ecu customization menu. This differs depending on if you're using DX or DXII. Once in there, there's a line for changing soot amount. It's named something funny, depending on the version of the software. Something like "amount of pm piling up". Pm something. Soot something. Change this to 2.3 and hit 'writing', key on, engine off. The DPR graph on the dash will go to three bars, which is the minimum needed to push the DPR button and get a response.

Now you can leave the customization menus and go to bcu diagnosis menu. From here you can download a burner event log, and you can set up a data monitor and record it.

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Smith772 · Jul 14, 2017

I have the DX2. As for the forced regen, I can press the regen button on the dash and it will regen on command without changing anything in the ecu. I will try to connect the DX2 right now and report back in a minute. One other thing, we pulled what we thought was the spark plugs but it looks like a probe on the end not a spark plug. Am I looking at the right part? They are mounted next to the burner injector.

Smith772 · Jul 14, 2017

Found these dtc's if this means anything

greasytshirt · Jul 15, 2017

If the DPR graph is between 3 and 9 bars, the DPR button will function. It will not do anything at 0-2 bars unless it was specifically configured to do so.
P2436 is not good at all. This very often means the atomizer has an unfixable internal fault.
P2030 means that the burner is not coming up to temperature. It's pretty generic, it has a lot of causes.

Go into the BCU, data monitor. Select the following things in this order.

Engine speed
Engine torque
Burner inlet temp
Flame temp
Burner outlet temp
target burner outlet temp
air pressure
atomizer fuel pressure
nozzle pressure
burner state

When these are monitored through an entire regen, you can get a good idea of burner performance. What I want you to do is to note where nozzle pressure is at all times. It will change when burner state changes. First of all, start the engine, turn on the exhaust brake (the burner will not attempt to fire with the ex brake on) and look at nozzle pressure. If it's above 8 psi, replace the nozzle. Cleaning it is an exercise in futility. If it's still above 8, replace the small braided line going to it. I imagine the nozzle is clogged. Any attempt to clean it by wiping carbon off of its face mashes carbon into the holes and makes it worse. I'm not kidding. It should be replaced every 150k, regardless.

When that's straight, the nozzle pressure should come up between 40-50 when it's preparing to fire the burner, and while the burner is operating. After it has successfully regen'd, and the burner is cooling down, when the burner state returns to it's resting state (and I don't remember what it says offhand) the pressure should return to under 8 psi. If it gets stuck at some higher pressure and P2436 sets, you need to replace the atomizer.

greasytshirt · Jul 15, 2017

While you're at it, while in the BCU diagnostic menu, there is a tab you can select and it'll allow you to download the burner event log. when it's finished downloading, exit that page then hit print. It should print to pdf. See if there are lost flame events, or other events with flame temps around 2400 degrees or so. This high temp is an indication of flame temp sensor failure (that long probe you pulled out). Lost flame events have multiple causes: poor ignition system (plugs, plug gap, wires, ignition coil failure) loss of combustion air (stuck combustion air valve, clogged combustion air port in the burner), burner mantle breakage, clogged nozzle, atomizer faults, etc.

greasytshirt · Jul 15, 2017

The DCU needs an update, and replace the batteries The latest DCU software is E0142. That code in the DCU suggests that your batteries are getting pretty crappy. Also I think that there's an ECU update due.

Hino123 · Jul 15, 2017

I definetly could have not said it better. Nice reply Greasytshirt. The P2436 as stated, usually ends up getting an atomizer any time it comes into my stall. If the customer declines to replace it,it usually comes back within a week or so with the same fault. Bummer

Smith772 · Jul 16, 2017

Thanks Greasyshirt, I will check all these things when I get to the shop in the morning. What is the DCU and where can I find it?

greasytshirt · Jul 17, 2017

Smith772 said:
Thanks Greasyshirt, I will check all these things when I get to the shop in the morning. What is the DCU and where can I find it?

The DCU is the Dosing Control Unit. It is located right above the DEF tank. It controls the DEF pump, which is right behind the DEF tank.
The BCU is the burner control unit. If you were to remove the left front fender, you'd see it above the burner.
The atomizer is a real joy to replace. It sits directly above the burner, right behind the BCU. You can get the atomizer out of its hole without removing the burner, but with a stubby 1/2 drive impact (with a swivel air fitting) and a Snap-On intermediate length 14mm swivel impact socket, you can have the burner out of the truck in about 15 minutes. There are fuel and air lines going to the atomizer, and the first time you replace one will be super aggravating, but be sure not to bend any of the metal lines or you will be fighting it for an eternity.

Smith772 · Jul 18, 2017

Looks like nozzle pressure stayed around 220 Kpa which is 30 psi no matter what it did. Monitored the regen but there is no flame I'm guessing due to a clogged nozzle. I downloaded the BCU event log but am having trouble with the print to file deal, I am limited in experience with this. Any advice, it will print to file but cannot seem to find it in PDF form anywhere.

greasytshirt · Jul 18, 2017

Smith772 said:
Looks like nozzle pressure stayed around 220 Kpa which is 30 psi no matter what it did. Monitored the regen but there is no flame I'm guessing due to a clogged nozzle. I downloaded the BCU event log but am having trouble with the print to file deal, I am limited in experience with this. Any advice, it will print to file but cannot seem to find it in PDF form anywhere.

After you download the burner log, close the download screen. On the main screen there should be a print button, you can see a print preview. You can view it from there.

At idle with the exhaust brake on, you should see approx 5-8 psi. If it's higher, unscrew the tiny braided hose and check again. If normal, replace nozzle. If it's still at 30, unscrew the line from the atomizer. If it's still at 30, replace atomizer.

Once you get it to burn, the atomizer still has to return to a correct pressure after the regen is complete. P2436 often sets because the pressure stays too high.

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Smith772 · Jul 19, 2017

Well....its regening and check engine light is off. Went through a full burn and nozzle psi went to a negative number after the regen completed and all codes went away. I am assuming if codes come up again the atomized is suspect. Also had a code for Low DCU battery that kept the CEL on but went away after I drove test drove and cycled the key, what is involved in replacing that battery if that code comes up again? And again, thank you for all your help on this one, couldn't have done it without you. I have been wanting to learn these Hino systems for awhile but couldn't find anyone who was familiar with them, it was a valuable troubleshooting experience.

greasytshirt · Jul 19, 2017

Smith772 said:
Well....its regening and check engine light is off. Went through a full burn and nozzle psi went to a negative number after the regen completed and all codes went away. I am assuming if codes come up again the atomized is suspect. Also had a code for Low DCU battery that kept the CEL on but went away after I drove test drove and cycled the key, what is involved in replacing that battery if that code comes up again? And again, thank you for all your help on this one, couldn't have done it without you. I have been wanting to learn these Hino systems for awhile but couldn't find anyone who was familiar with them, it was a valuable troubleshooting experience.

If you get good at Hino burners, you'll be very popular.

The vehicle batteries or connections are bad. The dcu is seeing low voltage during cranking. It does not have an internal battery. I probably worded that wrong.

Now, if possible I'd like you to put the soot at 2.3, set up those parameters to monitor in the BCU, and monitor a whole regen from start to finish. Save it and email me the .text file and I'll analyse it.

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