OrchardPerformance wrote: ↑Mon May 13, 2019 8:47 pm
Without even looking to check I can say you are looking at anything from 12 to 35 bar for pressures depending on the injectors so pulse width is all over the place.
In terms of running the engine (ignoring emissions and knock limited stuff) then any pressure around 20bar will do and adjust the fuel from there.
Probably worth just fixing the pressure and adjusting fuel until you can start it as normal.
Are there no flow rates for those injectors published?
BMW N20/N55/S55 is 50-200 bar; newer engines push 300 or maybe 350 bar. Because of the relationship of pressure to flow rate, 200 bar is only 2x the flow of 50 bar (square root of the ratio). The engine in question here may be old enough that the pressures are lower.
For my N20, I run 50 bar at idle (785 RPM, 30 kPa MAP) and the injector pulsewidth is around 1.2ms. As far as I can tell, deadtime on these injectors is close to 0.0ms, though I'm sure it's closer to 0.1-0.3ms. At 6700 RPM making around 200-210 rwhp, MAP=182kPa, fuel pressure = 200bar, pulsewidth is 5.3ms. This corresponds to about 213 degrees of crank rotation, if I'm doing the math correctly. The limit is a little under 360 degrees, as the positive rail is shared between two injectors operating on opposite crank cycles.