No volts on Injector 1 cable

[jerry486]

Need some advice what to try next.
Error Code: P0201 - Injector Circuit/Open Cylinder 1
325i SE 2008 3.0 Petrol

I'm not getting any power on the injector plug.

I've pulled out the DME and mosfets are all good.
I've checked continuity on plus and ground all the way from the DME plug to the injector plug - all good.

Any other tests I can do? Where else does this circut go to?

[bmwmike]

Have you seen bimmerprofs site? They might have some info around mosfets and injector power.

[jerry486]

Thanks Mike, I will take a look.
I have to also run a 10 sec test at the ignition stage (volts on the injector plug) - Does this look like normal behaviour to you?
Shall I uplug Cyl2 and compare, will in manage on 4 cylinders?

https://www.youtube.com/watch?v=DeOKF7Ulz3I

I have also found out I have different index injectors installed (someone obviously had issues in the past with this)
Cyl1 - 01
Cyl2 - 01
Cyl3 - 09
Cyl4 - 09
Cyl5 - 01
Cyl6 - 01

[bmwmike]

jerry486 said:

Thanks Mike, I will take a look.
I have to also run a 10 sec test at the ignition stage (volts on the injector plug) - Does this look like normal behaviour to you?
Shall I uplug Cyl2 and compare, will in manage on 4 cylinders?

https://www.youtube.com/watch?v=DeOKF7Ulz3I

I have also found out I have different index injectors installed (someone obviously had issues in the past with this)
Cyl1 - 01
Cyl2 - 01
Cyl3 - 09
Cyl4 - 09
Cyl5 - 01
Cyl6 - 01

Doesn't seem plausible for zero volts on an injector to be normal unless the engine is off or there is a fault? If the DME is cutting off the injector, there should be a code.

Have you tried a different injector in that pot?

[jerry486]

I have not tried a new one yet.
Also since these seems to be a mix of index 1 and 9's I might go with a 9, or two so that cyls 1-3 are all index 9 (same on one bank).

[bmwmike]

Considering there is voltage showing briefly on your volt meter and then goes to zero, and all other things like continuity and mosfet are confirmed as working, a duff injector would seem most likely, as its not strictly zero volt on the supply line is it, unless i'm missing something.

[jerry486]

Great, thanks Mike!
Last question - Can I swap this index 1 with an index 9 without having to code anything?

[bmwmike]

I'd try it and see if it runs at least.

To do it properly you need to code it, but for a test, i don't think so. All you need to prove is if it works or not, not that it runs properly.

[jerry486]

Is it hard to code it in? I suppose I could leave that last bit for the garage to do it for me.
I will also need a tool for the injector, won't I?

[bmwmike]

ISTA will do injector coding

You need a new coupler thingie. Not done one myself. Should pull out easy enough. As a test i'd just do it tbh and if it works, you know what you need to do.

[ashenfie]

It hard to diagnose with voltage alone , you really need something like a PicoScope or similar as that will give you a view of the frequency. A long while ago the AA used a meter with Frequency range at around 100v to diagnose a an ECU issue, where one of the injectors was not firing in my old Audi.

[popeofmick]

Be cautious when swapping injectors round, the small black PTFE seal should be changed. BMW have a tool but I fashioned something using a pen lid it worked fine. I have changed injectors on all cylinders multiple times when I was chasing a misfire on my 330i using this method.

[jerry486]

Thank you Guys!

I have now replaced the injector and my engine is running smooth again!
Initial quote £1,800, final bill £80!!!
I really enjoyed the whole process of getting my hands dirty.

[bmwmike]

Well done, glad its sorted. Someone else had similar result with an n53 recently too, 2k bill down to peanuts.

Probably worth you buying up index 11's as you see them on ebay in case those index 1's start to fall off their perches.

[jerry486]

Yeah, that's something I need to think about. I now have 3x index 9 and 3x index 1's installed. Maybe just make them all 9's?
The condition of the index 1 I pulled out makes me wonder how long until the other ones start dying.

[Ian Geary]

Morning,

Well done.

Your final bill of £80...was this for a new index 11 injector + coupler ring?

For an n53 engine?

Or was it something else?


I think mine needs injection throwing at it but can't see BMW index 11s for less than £250, plus another few quid for the coupler.

Thanks

Ian

[jerry486]

Hi,

This was for a refurbished index 9.

[Ian Geary]

Thanks