Page created for some verifications and notes. Please edit / update.
BMW M50 non-Vanos 88 pin harness connector
- exact engine type (and year) ? ...
- trigger measurements and triggerlog captured during cranking
- vemslog captured during cranking
We'll review the vemslog and triggerlog captured during cranking (ignition and injectors disconnected or disabled by pulling fuse)
- this is rather simple, and will inform us if we should investigate the trigger setup or output configuration
Getting no fuel or spark with the ECU with motronic88 connector
During setup (regardless of harness connector), first one does NOT want to get fuel or spark, but wants to see good sensor readings including TPS, CLT, MAT, MAP and InputTrigger/TriggerLog.
So at minimum one should specify that RPM=0 in VemsTune (or getting good clean RPM, or perhaps sometimes good, but jumping back to 0, or double of real RPM, or ...). The vemslog contains some information, but capture triggerlog anyway.
Some possible (common and not so common) reasons:
- plugging a motronic88 to a different engine, eg. M50 nonvanos (VR/VR) ECU to M50 Vanos (eg. M50B25TU ) engine.
- of triggers InputTrigger/TriggerLog and [VT help/triggerlog]
- of outputs
- or [safe mode] (easy to save and upload full config with verified outputs. Bogus output configured to injector channel might flood the engine with fuel, bogus output configure to ignition output might blow ignfuse or even igncoil, so before uploading the config really verify outputs are not misconfigured in it)
- But there are of course other possibilities
- eg. VR sensor+wheel are analog beasts, so based on DC bias or signal level it might be possible that signal level is reversed, or on the edge of suitability (works with one ECU but not with the other, or only >180 RPM ... and might need adjustment)
- and more (sometimes easy to diagnose with capturing triggerlog and vemslog and few measurements, sometimes might need special measurement, eg. with oscilloscope although that is rare).
VR,VR trigger Ohm measurement (very simple)
This can confirm things, or warn of some fundamental issues (like sensor disconnected, or plugging in M50 non-Vanos ECU to M50 Vanos harness)
- primary trigger VR (crankshaft)
- measure resistance between: mot88/67 and mot88/68 ... Ohm
- secondary trigger VR (camshaft)
- measure resistance between: mot88/16 and mot88/44 ... Ohm