N51 Fuel Pump Current Draw & Duty Cycle Specs?

[jvb6806]

2010 BMW 128i N51

I am throwing intermittent lean codes for both banks (29E0 & 29E1) and trying to narrow down the suspects. The codes first came up at an autoX that was heavy on the rev limiter in one section, but they popped back up last week on a 6 hour highway drive holding 3k rpm for a good chunk of it.

Short Term Fuel trims are + or - .5% but my long terms are between +14-17% which causes my concern.

There are no vacuum leaks or intakes leaks, MAF is clean and signal is within range at the DLC.

I have checked the fuel pressure at idle and it was at 75psi (spec) but I was wondering if anyone has the specs for the current draw of the pump at idle and under load.

I know that the fuel pressure regulator and the fuel filter and built into the tanks on these cars but does anyone know if the fuel pump speed is set by pulse width modulation or does the in tank regulator do everything. If so does anyone have the duty cycle specs for idle and under load?

I would rather do a pull with a scope in my back seat as opposed to a fuel pressure gauge under my windshield wiper.

The service information site I use tells me to "See DIS test schedule".

Thanks in advance.

[takrdown]

Did you ever get this resolve? I'm having something similar.

Thanks!

[jvb6806]

Originally Posted by takrdown

Did you ever get this resolve? I'm having something similar.

Thanks!

No, I never found the specs. This started happened near the end of the season, and usually only when I was racing. The fuel trims seemed to go back to where they should be under normal driving so I put the car away for the winter and haven't thought about it for a few months. I'm going to keep an eye on it and do some logs once the autoX season starts and see if there is a lean spot somewhere.

The car has a tune from TMS and the issue started shortly after I got my ECM back. Everything else is great with the tune, just the lean codes if I bump the limiter in 2nd. I just have to keep my fingers crossed for a slow course or a very fast course when I race. The motor hasn't blown up or started pinging... so just went with it.

My guess is that their map is just super lean at the rev limiter before it hits fuel cut. I tried to find a map that changed the limiter into a hard spark cut instead of the soft fuel cut limiter but I had no success.

If you find the draw specs for the fuel pump please let me know.