2008 535i Idle / Fuel Issues

[Psychengineer]

Since Bimmerfest is now effectively defunct, I thought I would copy a year's worth of troubleshooting here in hopes it helps someone else. I'll copy all the troubleshooting I did here and say that the solution was changing out fuel injectors in bank 2. No one ever returns to post their solutions.

So a few things have changed, same problems exist. Since my last post, I moved to Ann Arbor, MI (BMW was put on a vehicle hauler from Frenso to Stratford CT, then I towed it on a trailer to Michigan. The roads weren't too kind, leaks seem to be worse, but other than that still the same.

Here's a recap of what I've done so far in chronological order (all parts OEM or Bosch except plugs):

ORIGINAL PROBLEM: FUEL TRIM AT -18% AT IDLE, ROUGH IDLE

Changed fuel tank vent valve
Changed 2x VANOS
Changed 6x Coils
Changed 6x Plugs
Cleaned throttle body
Injectors tested good / seals replaced
Injected SeaFoam into intake, added to oil and fuel tank
Walnut washed intake, was really bad, now clean
Changed crankcase vent hose (gates emission control hose)
car stalls due to high pressure fuel pump over current / under voltage)
Changed fuel filter
Changed low pressure fuel pump
car stalls again for hpfp oc/uv
Changed high pressure fuel pump, remanufactured from FCAero
better crank, fuel still withholding -18% at idle)
Changed fuel pressure sensor
Changed turbo vacuum lines
no change in performance

At this point the control arm bushing is worn to the point I will have to change it before driving it too much further, and the transmission fluid is low again, jerky shifting. I'm debating on selling the car as is, but after I've put a few thousand into it and at least a week of labor, I'd really like to finally get to the bottom of what's wrong. Does anyone have any other theories? I've heard the o2 sensors could affect idle, however the idle is rough in the first 30 seconds after start and then cleans up afterword for the most part (OL/CL), so in theory I would assume the o2 sensors are doing their job adjusting correctly.

Here are the codes it had before I changed the high pressure pump:

30FF - Turbocharger, charge-air pressure too low
2DED - Power Management, closed-circuit current violation
2A15 - DMTL, minor leak
29DC - Cylinder injection cutout
29D0 - Combustion misfires, cylinder 4
29D1 - Combustion misfires, cylinder 5
29D9 - Misfire at low tank fill level
29CF - Combustion misfires, cylinder 3
29D2 - Combustion misfires, cylinder 6
29CC - Combustion misfires, several cylinders
29CE - Combustion misfires, cylinder 2
2F9E - Thermal oil-level sensor

I'm not getting any of these codes currently after I reset them after the fuel sensor change last week, however I haven't been able to push it hard with the transmission fluid low and a bad control arm. She cranks well, drives around town well enough, idle is mostly smooth once it's warm, just still at -18% LSHFT, unchanged from the beginning.


***Updated Solution***

Brought it into BMW of Ann Arbor. They recommended changing injectors, so I bought all new injectors from FCP Euro and coded them in with an Autel MX808. While coding them, the values in the DME for the injectors went to 000 000 and the car would not start. I had to have her towed back to the dealership where they told me several systems in the DME were reset (they only charged me for coding injectors, good folks).

When I got her back she purred like a kitten.

[Psychengineer]

During this issue, my fuel pump would randomly shut off and require 5min to be able to start again. I attributed this to leaking injectors, likely correctly, however a similar problem returned once the injectors were changed. Now the fuel pump shuts off on hot days or long drives and will not turn back on unless the battery was reset.

I quick review of similar problems online let me know that the EKPS (fuel controller), a little black box near the battery in the truck is to blame as it overheats. It's also known to overheat if the LPFP is updated to a newer model (it needs a newer controller as well, I'm told). So I've ordered the controller and it CANNOT be swapped without coding. I ordered the Bimmer-Tool coding kit and am waiting on it to arrive, will update if I can get it coded successfully.

[e91Owner]

Man, that is quite the trial for a car. Thanks for posting. The e60 forum here is a graveyard.

[Psychengineer]

Originally Posted by e91Owner

Man, that is quite the trial for a car. Thanks for posting. The e60 forum here is a graveyard.

Originally Posted by e91Owner

Man, that is quite the trial for a car. Thanks for posting. The e60 forum here is a graveyard.

Agreed. Also, coded the new EKPS in with the bimmergeeks tool, worked like a charm