Fuel injector problem - 2008 BMW 335xi

[JD!]

Our n54 engines (ths 335i included, me think) use super expensive and super fragile piezo injectors that have only been fixed (supposedly) in their 12th itteration (index 11/12). Index 11/12 can not/should not be mixed with earlier ones on the same bank (cyl 1-3 and 4-6) and in general they are a science on their own to source for a decent price (basically a forever hunting in junkyards, buying full sets).

Also, no matter what - they have to be coded/calibrated after install. Coding is usually done with a dedicated cheap laptop running ISTA (ISTA should be relatively straightforward to source for free if asked nicely on the correct thread on bimmerfest), or with the excellent BimmerGeeks ProTool app available for Android.

ProTool requires either a good quality cable, or one of the good WiFi OBD adapters, or their own dedicated BlueTooth OBD adapter (for BT, only theirs will work).

Sadly, the two leakers I had to replace were Index 12s. Put 11s in their place and those cylinders are fine now. The rough running cylinder I'm going to replace also has a 12.

I do wonder why these injectors are such duds. The previous owner bought them from a junkyard, and I wonder whether varnish from fuel evaporating or contamination from poor storage/install had anything to do with their failures. Back when I lived near one, I used to grab Index 12s from N63s at the pick and pull ($100 for 8 injectors - jackpot) and I never had a problem with them. Maybe them sitting in the yard with the fuel lines still installed and being careful about contamination was the reason for my success?

Regarding the coding, I use ProTool. What a great program, had it for five years now and it's paid for itself 10x over. Of course, none of the injectors in this 335i were coded right when I got it. Real gem of a car...

 

[GSCJR]

How's the engine vacuum at idle @JD! ?

 

[JD!]

Update on the car, new thermostat housing vs. old thermostat housing. Previous owner must've opened it and removed the thermostat.... real gem on my hands here, folks.

I'm probably going to lose sleep over how much fuel dilution there was with this and the two leaky injectors.

 

[RooflessVW]

.

 

[JD!]

Putting a different injector in cleaned up the idle. Runs fantastic now. I did install a known good Index 8 from my stash, the rest of the injectors are Index 11 or Index 12s. I know they say not to mix these, but it'll be good enough to hold me off until I can grab a good deal on a junkyard set.

With all new shocks and new front control arms, it's like a whole new car. Already falling in love with it.