[Poosik]

These codes pop up despite me clearing them. Past 3k rpm 70% WOT check engine light goes on. If ignored and car accelerated aggressively again, it turns off while still in motion.

Can it be just a bad connection at the rail where i had my jbd??

[Thecastle]

From the title are you stacking a jbd and a tune? Or are you running just a jbd.

[HeatherM35d]

Originally Posted by Poosik

These codes pop up despite me clearing them. Past 3k rpm 70% WOT check engine light goes on. If ignored and car accelerated aggressively again, it turns off while still in motion.

Can it be just a bad connection at the rail where i had my jbd??

If you aren't stacking a JBD maybe it's time for a fuel filter

[blowinsmoke]

I second the filter idea. I had a HPFP go bad you better hope thats not the cause.$$$$$

[TDIwyse]

Originally Posted by blowinsmoke

I second the filter idea. I had a HPFP go bad you better hope thats not the cause.$$$$$

Would you be able to share some information on what went wrong with your HPFP? Haven't heard of many failures with our CP3, so this would be a good data point.

[Poosik]

Originally Posted by Thecastle

From the title are you stacking a jbd and a tune? Or are you running just a jbd.

The codes came up with no stacking, just the bare bones tune.

[Poosik]

I can clear all code with BMWhat app, however if re scanned with different obd dongle and using Dashcommand Pro on iOS a "Permanent" LOW RAIL PRESSURE code is still found.

[Poosik]

Originally Posted by HeatherM35d

If you aren't stacking a JBD maybe it's time for a fuel filter

Thanks for mentioning the fuel filter. It's been changed about a year/12,000 mi ago.

[Mark M]

Originally Posted by Poosik

Thanks for mentioning the fuel filter. It's been changed about a year/12,000 mi ago.

Can't hurt to use some electrical contact cleaner and double check that the rail sensor harness is seated correctly. Google for pics of this connection to insure you have it oriented right.

How long have you been running the tune before these faults started cropping up?

[Poosik]

Thanks, Mark.
I ran the tune since 9/2015.
My fuel filter is about 15months old with around 14kmiles on it.
I ordered an new fuel filter from amazon, and needless to say hoping it will solve the low rail press codes.

[BB_cuda]

Originally Posted by Poosik

Thanks for mentioning the fuel filter. It's been changed about a year/12,000 mi ago.

I guess it is worth a shot if you got a tank of dirty fuel or something. 1 year of tanks would seem too early unless you got a contaminated fuel. I went 23 months between FF change but am considering switching to every 12 months.

As a test to rule out FF, you could disconnect FF on its outlet side. Hook a hose on temporarily to run output into a pan. Power up transfer pump and see if you get appreciable flow. I had same flow with old (23 month) and new filter. I was trouble shooting something else. Good luck getting her running again. If good flow with old FF, make sure to prime this lower press section of line free from air before trying to start again.