Year of Manufacture *: 2005 Engine Size and Code *: M57 3.0d ( Optional ) Scanner Used: Autologic
Hi All,
We've got an E91 330d (M57) in the shop at the moment with an "investigate poor running" condition when hot. Using AL we can see that the smooth running corrections for all cylinders are ~0 - 1.2 with the exception of cylinder 4 wich is 4.7 cold and raising to ~5.5 when hot, so we suspect a faulty injector.
So, the car gets driven into the workshop (running fine) and we switch off. Remove injector #4 and replace with new unit. Code the new injector correction value into the DDE and attempt to start..... nothing. It just cranks and cranks and cranks with no sign of firing. Double-check all the connections/fuel lines etc and all appears ok. Attemt to start, still no-go.
First thing was to check the car had fuel (been there, got the t-shirt....) as it had low fuel warning on. Put another 8ltrs in just in case. Hooking oscilloscope (Pico) up to the fuel rail pressure we can see the 0.5v plausibility value on key-on. However, during cranking there is absolutely no increase from the 0.5v showing no rail pressure. We have checked the fuel pump under the back seat is getting power. We have checked the LP fuel pressure at the outlet of the fuel filter and have 8.2bar during cranking. We have checked the cam sensor signal and it's present and OK. We have checked the PWM signal at the fuel control valve at back of fuel rail and is OK. As we are 99.8% convinced there is no high-pressure we have cracked (not undone) the joint where the HP outlet from the pump joins the rail and there is no fuel escape during cranking. We have checked the voltages at the HP pump volume regulating valve and all appear OK. We have loosened the bolts securing the volume regulator on the pump and can see a lot of fuel escape during cranking (so fuel must be getting to the pump). As an aside we also reloaded the DDE and EKP software to see if that would help but no change in starting condition. As we cant see ANY increase in fuel rail pressure we are now suspecting a fault in the HP pump, possible a broken shaft?
Forgot to mention we blanked all fuel outputs to the injectors (ball bearing in all the outlets)but there is still absolutely no increase in pressure at the rail..... We also clamped off the return line to the tank but still no change in zero fuel rail pressure.