2007 JO8E-tv . Reprogramming?

tjcezar

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I have a HINO 2017 jo8e-tv truck we just put in all new injectors. Truck flashes check engine after running for a bit. Code is for low pressure in fuel rail. I am aware that truck needs to be reprogrammed. is it possible that it what is throwing the code? Do I have to take to a dealer to reprogram for new injectors?
 

greasytshirt

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Injector coding isn't going to affect fuel pressure. It's more like fine tuning. You have a different issue. Fuel starvation or leaks in the high pressure side of the fuel system.

You should still get them reprogrammed
 

tjcezar

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Greasytshirt. Is it possible to reprogram if I don't have codes from paperwork with new injectors. The old cores were sent back in the boxes and we can not locate now?
 
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Hino123

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If you remove the valve cover you will find the trim codes on the tops of the injectors. They put them on little plastic clips right under where the wires to the injector solenoid terminals are. If you bought aftermarket injectors they most likely are not there. It sounds though like you purchased genuine Hino/Denso injectors. Write down the numbers AND take a picture of them. Then take them to a dealer or someone who had a copy of Hino software DX2. The balance rates really only come into play at idle. If the truck shakes violently at idle, but comes out of it at 1500 this could be related to incorrect balance rates. Could Be. You are also supposed to “re-learn” the fuel pump wham replacing injectors as well. With all that having been said. I’m with Greasytshirt, I do not believe balance rates would ever cause a low fuel rail pressure code. I would also suggest you DO have them programmed. Can you tell us the exact code it set for fuel pressure?
 

tjcezar

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So a little update. I did not have exact code for the low pressure in fuel rail as he couoldnt remember. We had put the project on hold a little but are getting back to it now. Unfortunately I am in the middle as truck is at the mechanics shop and he is the one working on it (im no mechanic). He is not familiar with Hino but is capable with most diesels. We need to track down the low pressure code and then the source. I really wish there was a source he could call for the fine details/specifics on these trucks if anyone knows of one. It could save us some time when troubleshooting
 

greasytshirt

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These fuel systems are similar to the Duramax.
This era of Hino is prone to getting debris stuck in the fuel supply system. The right angle fittings in the tank, rust chunks at the bottom of the tank, and the banjo fitting in the fuel filter are all common places for debris to clog.
This can be tested by splitting the system in half. Install a banjo fitting at the injection pump and attach to an auxiliary fuel source, then take it on a test drive of extended full throttle. Monitor fuel pressure desired and actual with a scan tool. If it maintains pressure, it's a supply issue. If it doesn't, it's a high pressure leak.

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