I ran out of time to work on it for the guy due to harvest and planting the last couple weeks, he took it to dealer and they said they found grass plugging his fuel line. few days later he calls me saying its doing the same thing. So i pull the bed, and cleaned out the junk I could find in the sending unit and tank. Then blew out the feed line from the motor back to the tank. It sounded like something shot out of it. Buttoned it back up and right away he says it feels like something is holding it back.
Its a different symptom now. before it was random extreme sluggishness with smoke due to the rapid loss of fuel. Now it is just very weak power throughout. I ramped the pressure to 23,000 at idle and it held perfect. also did at 2,000RPM. When driving though it never wanted to command over 17,000. it kept up with itself perfect the entire time, just never commanded over 17,000.
Things I have noticed.
P0404 set. EGR commanded Open % is always 0%, EGR Vacuum is always 13.9psi
Boost pressure wouldn't ever go much over 20psi absolute (6psi gauge). Tested wastegate according to book, at 30psi it starts to open and fully opens as pressure is increased. Tested MAP sensor according to book and as each in. Hg of vacuum was applied to the sensor, the reading in EFI live would drop the 0.5psi they want.
For some reason the throttle % reading was acting goofy on the drive. For awhile it just sat at 50.2% then it started moving a bit and stuck at 72.5% then once we got home we played with it in the driveway and it worked fine on his truck, went a tested it on another truck and worked perfect as well. These are just the numbers it displayed. if he let off the throttle the reading would stay up but the truck would drop to idle.
The #7 cylinder balance rate is out of spec. +4.55 in nuetral, +6.70 in drive. Ive never had a truck act like this due to an injector, but maybe this one is the exception.
I guess I am confused as to why the truck is simply not making power. Not sure where to start. Everything seems to be in check in the obvious areas and the fact that the computer just isn't commanding the pressure and such would be why error codes probably aren't being set. Where do I start on finding the culprit of why the engine is not commanding more fuel? The engine is not in reduced power as the book states P0404 cannot be set when in reduced power, and the RPMs will peg out just fine.
Could the vacuum be part of the issue? Thanks.
