2008 UD 2600 J08 Iddle issue

ud2600bbs

Seasoned Expediter
Owner/Operator
Hello everyone i have a 2008 ud with J08 and the problem i have is when the truck is cold in the morning starts fine after like q minute of warming up the engine Rpms start dropping and the truck wont accelerate and there’s black smoke coming out the DPF the weird thing is if i start the truck with the acceleration knob all the way up and works fine unless i turn it down starts doing the problem anyone has had this issue on a Hino ?
 

Hino123

Expert Expediter
Researching
Any codes? I can’t recall anything exactly like what you are experiencing but it could be a failing suction control valve. It definitely sounds fuel related. Gently tap on the side of the suction control valve and see if it comes out of it. Wiggle the common rail pressure sensor and monitor the fuel rail pressure. Obviously if the DPR is passing soot there is an issue there. I’m pretty sure you have UD software so we should be able to figure this out. How many miles on this unit?
 

ud2600bbs

Seasoned Expediter
Owner/Operator
Any codes? I can’t recall anything exactly like what you are experiencing but it could be a failing suction control valve. It definitely sounds fuel related. Gently tap on the side of the suction control valve and see if it comes out of it. Wiggle the common rail pressure sensor and monitor the fuel rail pressure. Obviously if the DPR is passing soot there is an issue there. I’m pretty sure you have UD software so we should be able to figure this out. How many miles on this unit?
Hello thank you for the response yeah its a weird issue the truck has about 500k but it has new injectors new pump with new scv i have tapped on the side of the scv but no change and the issue is only when the engine is cold starts fine about 1 min warming up the engines Rpm start dropping and gas pedal is dead wont rev I’ve check the ITV wiggled the harness on the pressure sensor no change I haven’t checked the fuel readings the last time i was checking the truck i had the engine on and hooked up the ud software and i was gonna test the turbo vnt and started the test and the truck changed it was idling fine and it would rev
 

Hino123

Expert Expediter
Researching
Man, not a lot to go on here. Possibly a skewed MAF sensor at cold temp? Could be trimming the fuel, bumping the idle may be giving it enough fuel to pull out of it? You can get a new MAF sensor on eBay or Amazon for under $30. Just google the part # on the MAF and it crosses to a 2007-2009 Toyota Tacoma I believe. OEM Hino MAF’s are like $220 I believe . I would suggest if possible to spend a little time in the morning monitoring the temps, injector balance rates, injection quantity, intake air temp etc. You may notice something not remotely possible like -40 degree ambient air temp. If you pm me your email I can send you a “expected value” chart for what is nominal at idle? If it is not setting any codes now I suspect it will shortly. I’m assuming the oil condition, level and air filter are known good as well. Possible egr valve issue flowing when it should not. The egr valve will not receive a command to open until 104 degrees. Can it get that hot in 1 min where you are?
 

ud2600bbs

Seasoned Expediter
Owner/Operator
Man, not a lot to go on here. Possibly a skewed MAF sensor at cold temp? Could be trimming the fuel, bumping the idle may be giving it enough fuel to pull out of it? You can get a new MAF sensor on eBay or Amazon for under $30. Just google the part # on the MAF and it crosses to a 2007-2009 Toyota Tacoma I believe. OEM Hino MAF’s are like $220 I believe . I would suggest if possible to spend a little time in the morning monitoring the temps, injector balance rates, injection quantity, intake air temp etc. You may notice something not remotely possible like -40 degree ambient air temp. If you pm me your email I can send you a “expected value” chart for what is nominal at idle? If it is not setting any codes now I suspect it will shortly. I’m assuming the oil condition, level and air filter are known good as well. Possible egr valve issue flowing when it should not. The egr valve will not receive a command to open until 104 degrees. Can it get that hot in 1 min where you are?
Thanks for the response i will monitor the injection quantity when cold also injector balance. And i will try another MAF I suspect the egr valve but i will
Digg in and come back once i test everything let me DM you my email
 

ud2600bbs

Seasoned Expediter
Owner/Operator
Man, not a lot to go on here. Possibly a skewed MAF sensor at cold temp? Could be trimming the fuel, bumping the idle may be giving it enough fuel to pull out of it? You can get a new MAF sensor on eBay or Amazon for under $30. Just google the part # on the MAF and it crosses to a 2007-2009 Toyota Tacoma I believe. OEM Hino MAF’s are like $220 I believe . I would suggest if possible to spend a little time in the morning monitoring the temps, injector balance rates, injection quantity, intake air temp etc. You may notice something not remotely possible like -40 degree ambient air temp. If you pm me your email I can send you a “expected value” chart for what is nominal at idle? If it is not setting any codes now I suspect it will shortly. I’m assuming the oil condition, level and air filter are known good as well. Possible egr valve issue flowing when it should not. The egr valve will not receive a command to open until 104 degrees. Can it get that hot in 1 min where you are?
Hello Hino123 i changed the Maf for a genuine hino and nothing change the engine starts up fine after two minutes Rpms start decreasing and the engine won’t rev even if you press the pedal
 
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