Hi I have been having some issues with my 2008 Hino 338. The truck loses power when the engine is working harder or it seems to be hotter outside and this causes the check engine light to come on. Sometimes it feels as though the truck wont make it up some of the hills it climbs. I am getting the P0087 code and the truck was recently brought to a dealer in the fall for recalls so everything is up to date recall wise. What my driver will do is turn the vehicle off and back on and the check engine light will go off and the truck has power again. Hoping to fix this in house to avoid the truck being pulled off the road and sent an hour away to a dealer. Thank you.
This is almost exclusively a fuel restriction.
Drain the tank and remove it. Remove both fittings from the top. Is there rust or chunks in the fittings? Its a narrow passage, stuff hangs up here. The tank is probably rusty. It needs to be very clean. If there is rust, address it or this problem will return.
Move over to the fuel filter. Remove the banjo bolts and adapter fittings from the filter housing. The inlet looooves to trap junk in the check valve. Blow out the line back to the tank. Clean out the fuel water separator and put a good fuel filter in it. I just about guarantee you'll find a blockage somewhere. A bumblebee in the fuel tank just cost one of our customers a $500 tow bill.