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Hey guys looking for some help on one here. Got a 2018 Duramax l5p has low power truck is deleted. And has dpf removed
No codes. Only getting about 50% engine load when at fuel throttle. Pretty much falls on its face about 2000rpm, Checked whole intake system for restrictions, checked turbo, changed fuel filter ( no metal in fuel) fuel pressures seem fine comparing commanded and actual. Cleaned map sensor. Anyone have any ideas on what I can check? I don’t know a lot about these fuel systems but I think it’s a fuel issue. I saw there is a service bulletin for a fuel pressure sensor pigtail I don’t have the codes for it but also read something about it will bypass one of the fuel rails is there is an issue? Does anyone have anymore info on that? I’m having the customer bring by his tuner stuff tomorrow so I can load the stock tune back in it to rule out any issues.
If fuel pressure matches desired under load within a few hundred PSI, then I'd say that clears the fuel system for now. No obvious fuel quality issues when you changed the fuel filter?
You'd mentioned low engine load. Does actual boost pressure match desired under load? Is the desired boost pressure actually boost, or is it barometric pressure? As in, is it calling for boost or is it in a limp home mode?
I saw that the DPF has been deleted, which is fine. Are the SCR and DOC still installed? If so, I'd be tempted to temporarily loosen the flange nuts and go for a short drive.
So since I posted this it has now turned into an intermittent issue. As far as boost pressure commanded vs actual it does not have a dedicated boost pressure sensor. Im assuming it monitors it off of turbo vane position which looks good
DPF and scr are both gone but does still have the doc behind the turbo. I was temped to loosen and drive but then it turned intermittent so I’m not leaning towards face plugged doc anymore.
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