2008 Hino 268 no power

Marauder

New Recruit
Mechanic
Hello, new member here. Have 2008 268 Hino, which has no power. No fault codes. Max 2000RPM, max speed 35MPH. Limp mode. Checked brake switch and stop light switch, replaced fuel filter, checked fuel lines for debris, removed exhaust, engine brake, checked DPF for clogging - all good. Have Hino DX2, when driving turbocharger speed always show 0 RPM
 

greasytshirt

Moderator
Staff member
Mechanic
There is no turbo speed sensor so it will always read zero.
Check the VNT, EGR and ITV with DX2 and make sure they all react correctly.
Use DX2 to check brake switch and stop lamp switch correlation. Is this truck air or hydraulic brake?
You can use the leak check function to see if it will make close to normal rail pressure.
 

Marauder

New Recruit
Mechanic
It is air equipped. I started from brake switch and lamp switch - shorted the one on rear axle, and removed brake switch from pedal, so both shows OFF. Zero change. DPR shows 1 bar. It's not trying to do regen.
 

greasytshirt

Moderator
Staff member
Mechanic
Brake switch concerns are very common, so I'd double check with DX2 to confirm they are both off.
 

Marauder

New Recruit
Mechanic
I doubled checked with DX2 - Brake Switch 1 - OFF, Stop light switch - OFF. Target VNT opening matches VNT actual opening. On Idle VNT 77%, pedal down all way - 68%. EGR all good also. What is ITV? Thank you!
 

Marauder

New Recruit
Mechanic
Just run fuel leak inspection - 1500RPM Common Rail Pressure 21715PSI, Target Common Rail Pressure 21750PSI, no problems with fuel
 

greasytshirt

Moderator
Staff member
Mechanic
Intake throttle valve. It's on the front of the intake manifold. The intercooler hose attaches to it. Make sure the throttle plate is tight on the shaft. It should also have three holes drilled in the bottom of it. Do a search to find the placement of the holes.

Sometimes on the 08-10 trucks the turbo wears out to the point it doesn't spin free and the truck will barely accelerate. Sometimes it doesn't spin at all.Spin the turbo by hand and put a little side pressure on it. If it binds up at all it should be replaced. A quick check is to unplug the mass airflow sensor and see if acceleration returns to near normal.
 

Marauder

New Recruit
Mechanic
Unplugged MAF, to double check - no change. I also removed air filter box to check for any damage, replaced air filter. When I drive I can hear turbo spinning. Removing throttle vale, to check the condition of it. Checked everything fuel/air/exhaust related.
 

Marauder

New Recruit
Mechanic
Throttle valve is full of oil. Despite that plate moves freely, it is tight on the shaft. Also there's three holes in the bottom. Turbo spins with hand. I'm out of ideas :/
 

greasytshirt

Moderator
Staff member
Mechanic
I'd actually put my hands on the turbo and confirm that it spins freely. It can't have any binding. This is a fairly common problem.
 

Marauder

New Recruit
Mechanic
Turbo spins with hand freely. Also tried spinning it with air compressor - no binding. Checked EGR - it's closed, and moving without problems. Noticed that crankcase filter is missing. Out of ideas
 

greasytshirt

Moderator
Staff member
Mechanic
2008-2010 trucks don't have crankcase filters.

We're running out of things to check. I've seen the tube to the boost pressure sensor get clogged up before. It's on the intake manifold.

How mush boost does it make on a test drive?
 

Marauder

New Recruit
Mechanic
Will go on the test drive and put pictures. Only idea get another Hino and compare all parameters. Injectors? I will check the boost pressure sensor. Thanks!
 

greasytshirt

Moderator
Staff member
Mechanic
Injectors don't really cause low power. Their failure mode is to overfuel, causing damage to the DOC and DPF.
 

Marauder

New Recruit
Mechanic
Got another Hino, and still nothing to hook up on. Intake air flow kinda low - 30g/s, 2000RPM reaches 100g/s, while good Hino idling 60g/s and reaching 2000RPM -145g/s. Switched MAF sensors - nothing, same numbers. No smoke nothing, engine in Limp mode.
 

greasytshirt

Moderator
Staff member
Mechanic
Has someone been in there messing with injectors? It's easy to mess up the fuel return line. If this leaks, the crankcase gets filled with fuel then the engine runs away.
 

moocowman

Active Expediter
Fleet Manager
Have you made the determination if the problem is really an ECM limp mode? Meaning, the ECM not allowing full power. When you're at wide open throttle, what's your "Calculated Load? The Calculated Load is supposed to equal what you're demanding from the engine. If calculated load is lower than what you're commanding, the ECM is telling the engine to derate. At wide open throttle, the Calculated Load should be 100%.
 
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