Did you do a compression test?Did a carbon cleaning after 70k miles and there was a limited amount of buildup, really no big deal. I also replaced all four injectors and the HPFP. Unfortunately, that didn’t cure the rail drop issue. This log was taken with the brand new parts installed and you’ll see that rail pressure drops 900 psi below the set-point and there is some knock only on Cyl 1. I’ve boroscoped the cylinder… while the amount of knock on Cyl 1 in the log isn’t particularly high, it’s clear that it’s lean as there are signs of detonation on top of the piston.
It stands to reason that Cyl 1, furthest away from the HPFP down the rail, is not getting enough fuel when the rail pressure drops. This only happens at WOT, there are no issues driving normally and there are no other drivability issues. I’ve also never gotten a code for rail pressure too low, which is kind of puzzling, but it’s definitely not following the set point.
Process of elimination here… the Injectors and HPFP are new, known good parts. I’m prepared to replaced the LPFP next. Am I leaving out any other possible cause?
I’m curious as to where others on pump gas tunes, particularly from EQT, see their LPFP duty cycle % at WOT. Mine sits at 92%, which from my understanding is maxed out. @Diggs24 , what would you say is a safe LPFP duty % range for a pump gas is38 tune?
Mine just had its 5th birthday as well. Such an awesome car and I like it as much as my last 3 series, a 2013 335i/Msport car. That too is an insanely well built car and kinda want another so I can park the GTI and get more done to her.Celebrated it's 5th Bday with wash and wax. One of the best cars I have owned.
Pinned the “killer dowel pin” & did the front main seal on the Cummins, threw a fresh air filter & pre filter off the the R33 on the GTI & swapped the OEM GLI wheels on so my Audi set could go out for powdercoat.
Would be a productive day, but the GLI wheels needed 15mm of spacer to clear the BBK so between that and the larger 225/45-18 they rub the fenders more than I’m ok with over bumps.
The other issue being the powdercoat shop is held up waiting on fans for their new spray booth.View attachment 262821View attachment 262822View attachment 262823View attachment 262824View attachment 262825
So now I’m torn. Do I just have my fresh set of MPSAS4 I’ve got sitting here mounted on the Audi wheels, find a different powder coat shop/wait for the local one & drive the suburban in the meantime.
I’m leaning towards just letting the car sit until I get the local shop to do the wheels because that’s been my plan all along…just feels wasteful to get 16mpg in the Burb for a week or two running it as a daily.