Same cylinder injector keeps failing

mfractal

Specialist
Nov 10, 2017
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E90 Sedan LCI 335i FBO MHD E40
My cyl2 injector keeps failing

First time was during a wot pull about a year ago. I got an epc and half engine light
Pulled the codes and saw

112201 injector, cylinder 2 , activation : Line disconnection.

Car was running rough and removing the error would just bring it right back

I went ahead and changed all 6 injectors for new Bosch ones.

Fast forward to December. I installed the fx-150 pump and went for a test drive with it

During a WOT pull I got the same thing, half engine light, epc and the following error

110208 - injector, cylinder 2, activation : Low voltage side short circuit to earth.

stopped on the side of the road, erased the error and the car restated fine

Next WOT pull - same thing but now restarting and erasing the error would not help and car kept running rough.
I bough another brand new Bosch injector abs swapped it.

Everything was good until today where I went to test a new map revision and by the end of the wot pull - same thing with same error on cylinder 2

Since I was like 200km from home I didn’t risk testing again and just babied it home.

I’m sure once I step on it tomorrow it’ll fail permanently again


Question is - what can cause the same cylinder to always fail?

I feel the installation of the upgraded Hpfp increases the wear on the injectors and me running higher E content as well but I’ve never seen so many injection failures with anyone , let alone on the same cylinder.

Any tips ?
 

mfractal

Specialist
Nov 10, 2017
80
27
0
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E90 Sedan LCI 335i FBO MHD E40
I thought my mods are in my signature but they aren’t so here goes :

F10 LCI N55 535i with a similar to ps2 hybrid, fx-150 Hpfp, Walbro “274” Lpfp, n20 plugs, oem coils, Dp, ic. That’s about it.
 

doublespaces

Administrator
Oct 18, 2016
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2009 E93 335i
This N55 has the 'solenoid' injectors right? On the N54 I've heard that running max pressure can cause the injectors to fail prematurely, despite not needing in excess of 3500 psi. What did your rail pressures look like prior to this injector failing and after the hpfp upgrade? In the early stages of this hpfp upgrade stuff, tuners may be sending everything they can.
 

mfractal

Specialist
Nov 10, 2017
80
27
0
Ride
E90 Sedan LCI 335i FBO MHD E40
This N55 has the 'solenoid' injectors right? On the N54 I've heard that running max pressure can cause the injectors to fail prematurely, despite not needing in excess of 3500 psi. What did your rail pressures look like prior to this injector failing and after the hpfp upgrade? In the early stages of this hpfp upgrade stuff, tuners may be sending everything they can.

yes, these are the pencil type solenoid injectors (EU6 in my case) P/N 13647639994

61G1I1pSq0L._AC_SL1500_.jpg


I was actually datalogging while it happened, here's the log



Can't say the pressure is too high to be honest, and it doesn't explain the same injector failing over and over :confused:
 
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Bnks334

Lieutenant
Dec 1, 2016
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This sounds like an electrical issue to blow through injectors like and with that type of failure. Check the ignition harness wires.
 

mfractal

Specialist
Nov 10, 2017
80
27
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E90 Sedan LCI 335i FBO MHD E40
This sounds like an electrical issue to blow through injectors like and with that type of failure. Check the ignition harness wires.

Was suspecting that too. Any ideas on how to diagnose it ?