Timing check

[Elliot2000]

Fuel coming out of the disconnected return lines is normal- u need to clamp it off when doing the test.

That fault code still relates to fuel pressure

Did you try running it with the air mass meter disconnected like I mentioned previously?

Also with it running have u tried disconnecting each injector one at a time to see if one doesn’t make any difference?

[arcon]

Yes I've run it without it plugged in, also without the manifold on and map unplugged

Unplugged each injector and no4 makes no change in engine tone. No slight change in tone and other two noticeable change in engine tone.
If it was a single injector (no4) though I'd have thought the knock sensor would throw a code up for it.
I did remove the injector though to have a look and if anything it looked clogged but that would result in excessive pressure rather than poor pressure.

Might see about replacing the injector anyway before looking at condemning the pump. Although before that I really need to hook up the bmw cable to get proper live data readings

[bearman68]

The loom isn't rubbing somewhere is it. I seem to recall it has a tendancy to rub somewhere near the oil dip stick? somewhere there on the LHS. Multiple faults sound very suspicious.

[iSore]

arcon said:

Yes I've run it without it plugged in, also without the manifold on and map unplugged

Unplugged each injector and no4 makes no change in engine tone. No slight change in tone and other two noticeable change in engine tone.
If it was a single injector (no4) though I'd have thought the knock sensor would throw a code up for it.
I did remove the injector though to have a look and if anything it looked clogged but that would result in excessive pressure rather than poor pressure.

Might see about replacing the injector anyway before looking at condemning the pump. Although before that I really need to hook up the bmw cable to get proper live data readings

The pump feeds the rail, and if three injectors work okay then so is the pump. It sounds like a shagged injector that is bleeding off pressure. Try pulling the plug from the front pressure sensor on the rail - that tells the ECU to run a default setting. Or swap injectors from 3/4........

[Elliot2000]

The two previous posts are spot on - swap injector 3-4 and see if daily transfers, if not then the small loom from the injector can go open circuit - check it with a multimeter end to end, u can get the section of loom direct from bmw for not a lot of money and it’s easy to fit.

I’d fault swap - then u know it’s the injector.

You can’t really look at the end of the injector you won’t really be able to tell anything- the actual fuel nozzles/ holes are too small to be seen