This time about the topic, regarding which I receive many questions:
a) are the piezo injectors of newer releases compatible with injectors of other (older) releases;
b) should all injectors be changed, so they release is identical;
c) is it significant, that there should be the newest release of injectors?
BMW AG defines: in case of problems replace old (with a black body) injectors with newer generation (with a gray body).
I haven’t seen injector with a black body. A long time ago, there were revocations, injectors of first releases (approximately: till the 4th release) were already in warranty time of the car. If still your car has injector/s with a black body, check with a local dealer – may be the revocation is possible, or at least you can get some discount for purchase of new injectors (if some problems with old ones are noticed).
If the body of your car’s injectors is gray, keep in mind: injectors of all releases ARE compatible! So, your car can have injectors with a different release for each cylinder! Even 6/7/8/9/10/11! Even more – there will be no negative changes in performance of the engine!
In several hundreds of engines with piezo injectors, seen and diagnosed in present, I never have taken care for releases of injectors to correspond or asked car owners to replace them all. ONLY problematic injectors are changed, very often (not less than in 4 cases from 5) the engines after repair had injectors of different releases. For the engine of my car, injectors of 3 different releases are installed: 7/9/11. And these injectors of different releases are installed with a purpose to confirm, that different injector releases are no problem. If I offer a solution for someone, at first I make sure, that it works – and there is no better way than to test it on my own vehicle. And yes, I’m very demanding to the quality of engine performance. I feel each misfire, each vibration. I feel when the engine runs in Homogeneous mode, when – in Stratified charge, when the regeneration of NOx catalytic converter is happening. And at the same time – I have NO reason to say, that it would be better if all injectors would be of one release.
MSD80 (and other DME, which are intended for management of piezo injectors) performs measurements of performance of injectors (tests of mechanical and chemical efficiency) for each injector in each performance mode (idle, low/average/high load, low/average/high RPM), in many points of adaptation maps! Differences of each injector from ideal are compensated! These tests are repeated on a regular basis, even if the performance of the engine is perfect. Independently from real parameters of injectors, unless they fit in the allowed “corridor”, all technological differences are completely compensated!
Even more – in this entry I even performed a simple experiment, which confirmed: parameters of injectors are stable, there is no difference, is the resource of injector 200 km or 200’000 km!
In the engine, which has completely new injectors, all of them were of the newest release. The other engine had injectors of several releases with different mileage. 4 of them: with the wear of at least 300’000 km. No quality differences in adaptation data dispersion, uneven performance of the engine were not detected!
So then – the release doesn’t matter unless the body of the injector is in grey color; wear of injector doesn’t matter unless it works correctly! Replace only injector or injectors, for which the diagnostics (live data) indicates any problems!
And finally, some important nuances for a successful result:
a) after replacement, the injectors have to be encoded. Taking into account the software bug, mentioned here, and as well as that there is no 100% safety, that other injectors previously were encoded correctly, I suggest – every time, encode ALL injectors (even if only one of them is replaced), for encoding use ISTA D (not INPA or a tool of some third side. INPA doesn’t check the integrity of injector’s data. Additionally: for N43 series engine – a sequence of injectors don’t matches sequence, displayed on the monitor. Regarding tools of third sides – there is no warranty, that the injectors will be encoded correctly); more about encoding read here;
b) after replacing the injectors, perform correct re-adaptation of the engine. I recommend to use INPA for data control, to make sure, that everything runs according to plan. At first, adapt the flywheel, then create fuel mixture adaptations, as described here;
c) pay special attention to warming-up of the Lambda probes. If it’s “late” – obviously, DME has some fundamental problems. Most often cause – incorrect encoding of injectors (incorrect data integrity).
And now, please make attention to this screenshot:
Injectors flow-rate correction data for idle/Stratified charge. Needless to say – perfectly working injectors!
Mileage of the car? 300.000 km. Injectors were replaced 220.000 km ago. Release? 02!