Stefans BMW E34 535 turbo
Engine specification
- Stock BMW M30B35
- Siemens 788 cc/min injectors (low impedance, 2 Ohm)
- Stock coil and distributor ignition
- Flyback uses TS diode and 6.8 Ohm/50W resistor pack (no peak-and-hold)
Short movie from the startup: (save as) [.MOV (24 MB)]
Remaining problems
I have used a Genboard v3.2 which has seen some tough situations in the previous car (replaced Atmel CPU, etc..). It's going to be replaced with a brand new v3.3 either way - but in case someone could tell me what's wrong with the current Genboard or where to look next I'd be happy.
- False triggering as soon as the wideband controller is activated (with mde02)
- Adding a 10K pullup at R30 did not help remove the false triggering. This means that trigger noise (maybe due to grounding sloppiness) is quite significant, above 500mV.
- sounds like your VR- does not merge into EC36pin26 GND right at the econoseal, but there is something "offending" between (like the fork to GND5 pins is closer to EC36pin26 than the VR-; GND5 pins are where the WBO2 gets it's heater- via the controller. Ground in the engine harness can sometimes be hard to get known)
- I made the harness according to MembersPage/PhatBob/UserGuide. VR- is directly connected to EC36pin26, from that pin there is about 5 cm of wire until it merges with all sensor wire grounds(CLT, IAT; TPS, VR sensor shield, ..) and then is run with about 40 cm of wire directly to a bolt on the head of the engine. All GND5 wires merge at this same bolt with the single GND wire. The cables are crimped together and soldered to a ring type connector.
- The ground wiringi is is pretty much how it should be, which is why I suspect the Genboard.. I will install the v3.3 and we will see, I will try this v3.2 on my own car later in January.
- False triggering is only an issue when the engine is not running!
- with the engine running, the VR signal pushes the adaptive threshold higher so this is quite good.
- Some false triggering while cranking, nothing serious (but should not be there, I know). Check MembersPage/PhatBob/UserGuide for ground rules. Most probably wouldn't worry at this stage ;-)
If the wideband fuse is in place and the engine is started everything works alright, no wheel errors and nothing out of the ordinary. We have tuned it some and can only face the fact that it's hard to tune this car in winter condition since we loose all traction above 4000 rpm on the E4. :-)
We removed everything related to the diagnostic connector and kept just some of the wires that went to the chassis connector (ignition, rpm, alternator, starter, oil pressure switch, cluster coolant temp, ..).
We then basically rewired most of the cable related to the Motronic harness - the injectors to get sequential firing and all the sensors because we made all new grounds and didn't want the signal wires to be cut short when connecting the Econoseal connectors of the VEMS Genboard. We did re-use all of the trigger cable and connectors! We didn't re-use the stock injector miniterm connectors, we got new ones from the VEMS webshop which are easier to disengage.
All in all I think me and Stefan spent about 4-5 evenings on the wiring, this could've been cut a lot shorter if we had done it before and knew how the stock harness was interconnected..
We re-used the "cable box" that encases the injector connectors. Very neat after we zip tied everything and closed it up.
Glory shot of the car.
