Big Truck I work on Hino trucks. I'll answer any questions I know the answers to.

[walemurphsprin]

we have an 08 hino that has no throttle response, wont go over 5mph until the brake is tapped or the accelerator is cycled, I have checked the brake switches and they are not staying engaged and the pedal switch is working properly, any help on what else to check would be great

 

[greasytshirt]

we have an 08 hino that has no throttle response, wont go over 5mph until the brake is tapped or the accelerator is cycled, I have checked the brake switches and they are not staying engaged and the pedal switch is working properly, any help on what else to check would be great

There's a pedal switch on top of the pedal that has a little ratchet adjustment. Turn it a quarter turn to unlock it, and press it down until the little plunger is pushed all the way in, plus maybe an extra click. The pedal return spring is not strong, and it doesn't always push the plunger back correctly.

Also check to see if the ITV has been modified. I've talked about it in depth, and there's a pic in a past post showing what it's supposed to look like.

Let me know what you find.

 

[jeffcarl]

Hello again Mr GTS
I have a self-inflicted problem: the box I put on my cab & chassis is too tall to back into my building. I have 11R22.5 tires on it. My rear axle is 21,000 lbs, tires are plenty capable. Now here's the questions: Can I use 225 (or 255) 70R-22.5 tires? That would reduce my truck height by 5". Problems are 1) tire capacity is 5070 ea, or 20,280, which is 720 less than the back axle, is this a deal breaker? 2) various computer changes necessary for speedo & abs, can this be done? 3) will I be running rpm too high at highway speeds, and can if so can the Allison be adjusted for higher ratio.

Is this just stupid, or is it feasible?

 

[walemurphsprin]

I have adjusted the brake pedal switch already plus I monitered the brake switch values in DX. The intake throttle valve has been modified and has no play. I also pulled the egr valves and checked and cleaned. Also not sure if related when the throttle I'd released there is a loud air puff noise coming throght the intake

 

[greasytshirt]

I have adjusted the brake pedal switch already plus I monitered the brake switch values in DX. The intake throttle valve has been modified and has no play. I also pulled the egr valves and checked and cleaned. Also not sure if related when the throttle I'd released there is a loud air puff noise coming throght the intake

Will the vnt move through its whole range, with target and actual within 5 percent?
Check the turbo for axial and radial end play. Does it spin freely, or does it stick?
Is there oil on the mass airflow sensor?
Does it have air or juice brakes?

Are any filaments in the brake lights broken?

 

[greasytshirt]

Hello again Mr GTS
I have a self-inflicted problem: the box I put on my cab & chassis is too tall to back into my building. I have 11R22.5 tires on it. My rear axle is 21,000 lbs, tires are plenty capable. Now here's the questions: Can I use 225 (or 255) 70R-22.5 tires? That would reduce my truck height by 5". Problems are 1) tire capacity is 5070 ea, or 20,280, which is 720 less than the back axle, is this a deal breaker? 2) various computer changes necessary for speedo & abs, can this be done? 3) will I be running rpm too high at highway speeds, and can if so can the Allison be adjusted for higher ratio.

Is this just stupid, or is it feasible?

What year is the truck?

1. Idk anything about configuring a truck.

2. Yes, but it depends on the year. Early trucks used a handheld device that is fairly rare. Later ones are easy.

3. What rpm does it run now at your regular top speed? No, the Allison has fixed gear ratios. A rear gearset change might be feasible if we can calculate what ratio you'll need. Get me the year, and ill try to remember to grab the right book.

 

[walemurphsprin]

The play in the turbo seems acceptable. It move through the entire stroke fine. Seems to spin freely. Found slight oil on the mass airflow is it acceptable to clean it. It has full air brakes and the tail lights are working. They are LED so no filaments

 

[greasytshirt]

The play in the turbo seems acceptable. It move through the entire stroke fine. Seems to spin freely. Found slight oil on the mass airflow is it acceptable to clean it. It has full air brakes and the tail lights are working. They are LED so no filaments

Contact cleaner works well if you don't have the special maf sensor cleaner.

 

[walemurphsprin]

I cleaned the sensor and test drove it is still not accelerating past about 8mph then it will take off and run fine

 

[greasytshirt]

The play in the turbo seems acceptable. It move through the entire stroke fine. Seems to spin freely. Found slight oil on the mass airflow is it acceptable to clean it. It has full air brakes and the tail lights are working. They are LED so no filaments

unplug the connector from the rear relay valve and try to drive it around the parking lot with the connector both open and a jumper across the terminals.

 

[walemurphsprin]

With the switch unplugged engine is derated but not the same as before with it jumped it is acting the same. But now on my test drive the DPR level jumped 5 bars at once and is now calling for a regen

 

[walemurphsprin]

I did the regen it completed fine, the system protection temp is high dpr outlet was 1500. any took for one more ride it is still acting up, will have to continue tomorrow

 

[greasytshirt]

I did the regen it completed fine, the system protection temp is high dpr outlet was 1500. any took for one more ride it is still acting up, will have to continue tomorrow

That's above the threshold for melting it. There is a dpr recall right now, you may get a free one. Don't clear the system protection data. Check the dpr temp sensor wire connectors on the chassis side for a broken wire. Known weak Point, they sometimes break inside the insulation.

 

[greasytshirt]

With the switch unplugged engine is derated but not the same as before with it jumped it is acting the same.

What this tells me is that it's now an engine control issue, rather than interference from the brake/transmission anti-stall function (totally made up name for it).

I'd set up DX to look at engine rpm, APP inputs, scv driving current value (actual scv current), final value of pump current target(target scv current), injection quantity, and both target and actual common rail pressure. Do a lot of starts and stops. If you have the graphing macros, overlay actual and target scv, actual and target common rail pressure, and the app sensors.
During the interval where it fails to accelerate but works correctly when you tap the brake...This interval is where you want to be looking. Something is not responding correctly and you should be able to spot it.

I'd love to be there to do it myself, because it's a lot easier to do that rather than try to explain it!

Now for the bad news: We've had countless trucks come and go with this same issue, and it's almost always the same thing: That stupid brake pedal switch. The air brake trucks are much less susceptible to it because the switch in question is on the rear relay valve. If APP inputs, scv actual and target, rail pressure actual and target all immediately respond, and the ITV isn't fouled up and slamming shut, then it's quite often the turbo. If you quickly rev the truck in neutral and then let off and the turbo responds by surging, it's often the turbo's fault.

For those reading this that don't know what compressor surge is, here's a good example. http://youtu.be/LZUbo_mNDZM?t=20s

 

[walemurphsprin]

We are sending the truck to the dealer for the dpf. Could it be possible to argue the turbo failed ad a result of the dpf being restricted.

 

[greasytshirt]

We are sending the truck to the dealer for the dpf. Could it be possible to argue the turbo failed ad a result of the dpf being restricted.

Ehhh...I don't think so. You could argue the inverse, though.

 

[coalminer]

Well, I have not driven my truck in the last month or so, its sitting in the parking lot of where I work now, we used it to move the business. So the other day I got in there to start it for a few, and turned the AC on because I was hot, and the AC didn't engage, the compressor was just barely moving, like the coil was not pulling it in all the way. I turned it off, figured I would check it out this weekend. So im tracing things down and when I use my voltmeter I am showing about 12.06 volts, when the truck is running, it takes me a minute to realize, that's not right. The alternator light was not on, but when I turned the truck off and the ignition back on, the light didn't light up at all. I checked the 140 amp fusible link and its ok, there is voltage at the alternator, so is the alternator internally regulated or could the problem be somewhere else?

Figured I would see if there was something easy to check before I pulled the alternator off, any help would be awesome, thanks!!!!

By the way, its a 2005 Hino 268

 

[greasytshirt]

Well, I have not driven my truck in the last month or so, its sitting in the parking lot of where I work now, we used it to move the business. So the other day I got in there to start it for a few, and turned the AC on because I was hot, and the AC didn't engage, the compressor was just barely moving, like the coil was not pulling it in all the way. I turned it off, figured I would check it out this weekend. So im tracing things down and when I use my voltmeter I am showing about 12.06 volts, when the truck is running, it takes me a minute to realize, that's not right. The alternator light was not on, but when I turned the truck off and the ignition back on, the light didn't light up at all. I checked the 140 amp fusible link and its ok, there is voltage at the alternator, so is the alternator internally regulated or could the problem be somewhere else?

Figured I would see if there was something easy to check before I pulled the alternator off, any help would be awesome, thanks!!!!

By the way, its a 2005 Hino 268

Yes, it's internally regulated. Seems to me like it's a simple alternator failure. Is there a place near you that can test it first?
You know, I've never personally changed one. We've changed a few, but the alternators and starters seem to hold up pretty well.

I'd clean up all the ground wires you can find too. Just because. Especially where the negative cable bolts to the frame, and the body to frame ground, left rear corner of the cab.

 

[coalminer]

Thanks for the advice on the ground straps will clean them up. Seems like that is a very common alternator, given all of the trucks that is listed on this ebay auction:

New Alternator Freightliner M2 Hino 145NA 165NB 185NC 238nd 258nd 268NE 268ANJ | eBay

For $90 I think I will give it a try, they have been on Ebay for a while plenty of feedback, so must not be that bad.

 

[allways]

I have the exact same problem on a 2010 flat bed tow truck. Brake switch replaced and data for switch has been monitored and PCM is seeing switch input - and brake lights work flawlessly. Tap brake or throttle during accel and takes off like normal. Have been trying to resolve for 6 month.

Truck is currently down for repairs and as soon as it is back up will be testing a few more items.
This truck has 375k miles and has been happening for well over a year & at least 100k miles. Also am chasing a code P0087 - low fuel rail pressure detected - loses power up hill under load - loaded with a vehicle - fuel filter is new and fuel will gravity flow from tank to fuel rail - no apparent restrictions. At this time and we are replacing the SCV as a first attempt to repair. Also found MAF bug screen coming loose and almost sucked into intake tube - MAF will be replaced also and we will see how she runs after these items are changed - MAF was also oil contaminated. Recall for DPR performed and replaced, Recall for ECM recalibrated & exhaust brake adjusted.

Have 7 of these trucks 09 & 10 and only this one is giving us a problem. Took truck out of service to repair oil leak from front crank seal. Hard to install without tool and tool is on back order at this time.

Will update all on results. Please post a solution if anyone has seen this problem and has fixed it.

Thanks,

Allways