Bad injector??

[bluebeemer]

So I had a rough cold start and threw a CEL - cylinder 4 misfire on my '09 135i. I swapped #4 coil with #1, and another rough start and cylinder 4 misfire. I FINALLY found my spark plug socket and cylinder 4 plug was wet and black, vs all others gray/tan and dry. Swapped cylinder #4 plug with #1 plug and did a cold start. Still a little rough but no CEL. Pulled #4 plug and it is already black after a two minutes at idle. Bank 2 Short Term Fuel Trims were still running ~ negative 12 or 15, and slowly climbed closer to zero after a minute or two - similar to previous starts.

Am I missing something or is it time to do my first injector change out? Fuel rail pressure bled down to 60 pounds overnight with the car idle. Is this "normal"?

Any advice would be appreciated...

[optigrab]

if the plug is wet the injector will need to be changed. They cannot be cleaned. Best to change a whole bank at a time if you cant do that please see the notes below. Injector version is important.


Injectors with index 11 and higher have a different calibration and construction than injectors with index 10 and lower.
Due to this difference, the injectors with index 11 and higher and injectors with index 10 and lower cannot be mixed on the same engine bank

[bluebeemer]

Thanks!! I checked and I have index 5 injectors in all 6 slots. Looks like FCPEuro and ECS are charging $200 each for VDO or BMW brand with decouplers and seals. I am going with new injectors as I don't trust a refurb. Any opinion as to benefit of replacing all 6, instead of just bank 2 cylinders 4,5 &6?

I guess I am gonna have to learn how to code these BMWs. Looking at OBDinnovation.com for software and cable for about $40. Actual replacement looks easy....................

[optigrab]

replacement is not hard just make sure you dont put the hold down bracket on backwards otherwise nothing will be holding them in. Some are probably loose now because the tabs break off.

I used this tool when i did mine you have to have it for servicing but not required for a new install because the PTFE sealing rings are already compressed. If you get a tool I would get a few new PTFE sealing rings some of the bores will be dirty you can use the old injector and a new ring sealing to clean them. Did 3 with the tool and 3 without having the tool makes the job much easier.

http://www.precisionraceworks.com/in...&product_id=78

Only use the following if injector bores are dirty.

- To clean injector bore, slide injector, without uncoupling element but with new PTFE sealing ring, in and out of injector bores several times. Replace PTFE sealing ring after cleaning.
- Clean contact surfaces of uncoupling element and cylinder head. Replace uncoupling element

• Work only on fuel system when engine temperature is below
40°C (104°F).

• Unscrew the fuel tank cap to release pressure in the tank before working on the fuel line.

• Replace the teflon 0 -ring when fitting and removing the fuel injector. This also applies to an injector that has just been fitted and has to be removed again after an engine start.

• A new injector with a new teflon 0-ring should be fitted as quickly as possible Sealing ring swells up once cap is removed.

• Also, be sure that the injector is correctly seated when installing. The injector one hold-down must rest on both injector tabs, otherwise thenecessary force is not applied to injector.

• Before servicing fuel system, remove ignition coils and cover spark plug holes with a cloth.

• Replace fuel-fouled ignition coils.

• Due to conversions taking place in the DME control unit, the final digit of the values entered may differ slightly after they have been stored. This does not indicate an input or control unit error.



Hold-down bracket to cylinder head 13 Nm (9.5 ft-lb)
High pressure line to injector 23 Nm (17 tt-lb)
High pressure line to fuel rail 23 Nm (17 tt-lb)

[optigrab]

If you can do all 6...there were 12 different revisions for a reason you are living on borrowed time.

[bluebeemer]

Full set on the way from FCPeuro. They come with seals installed/capped and decoupled. Bought a 7th spare seal and decoupler just in case. Also a removal tool and cone/caps in case I need to swap a seal.

I do hope the index 12 last more than 55k miles.

Thanks to everyone who offered advice!