The engine is a bmw s50b32 converted to single vanos on intake with a trigger with one tooth installed at ~60 degree before missing tooth, the vems trigger log also shows this.
The ecu is unit 7148, vr vr and 4 pfet for vanos control
The car runs perfect in wasted spark mode. Is making 806hp at 7700rpm and 1.5bar boost. Now I'm trying to make vanos work on intake so I can make boost faster, now I see 1bar at 5000rpm.
Vanos is working good from the logs I made but I have problems with the secondary trigger.
When cranking the signal is very good and stable, the problem is when I start the engine. I have to many sectrig and I can't rev past 1300 (similar is the symptom when VR is reversed), the ecu seams to reset as the afterstart flag comes on.
I tried to play with the filter settings (minimum angle 39, maximum 120) and i manage to filter it a little and now i receive only sectrig pos bad and the engine revs, as you can se in the logs at ~4000+rev the trigger error is gone!!!
I made the following:
- Changed the sensor.Same result
- no need to try both, just try the good GenBoard/Manual/VrSensor/Polarity,
- Changed the polarity of the sectrig. the signal moved to the second tooth after the missing tooth and the logs shows ~350 degrees. This was wrong because the trigger was installed at ~60 ( 9 tooth before missing tooth )... anyway with the polarity change same sectrig errors
Don't set VR polarity according to position. Just set the right GenBoard/Manual/VrSensor/Polarity
- I changed the vems ecu with a similar one ( vr vr ). same result
- I use a oscilloscope to see if the signal has noise or something. The signal is good, a little noise when cranking but good signal when the engine starts.
- can we see the scopeshot ? Does the pulse start with positive peak than negative peak ? Sure ? What is the amplitude (at what RPM ?
- What is DC voltage ? (VR sensor DC voltage can be measured even with stopped engine, with ignition on)
- I started with firmware 1.1.96, with this firmware the car worked for a few years with the old ecu without the pfets. Now i have firmware 1.2.11
I will try to look again at the wiring, grounds and maybe rewire the crank and cam triggers!!!
- I don't know what "ignore sectrig pulses above" and "maximum primary edge between secondary edges" does?!?! How should i configure this settings?
- after the sectrig polarity is correct in HW (we're currently at that stage), the sectrig pulse must be examined (in theory and in triggerlog).
- If there is only 1 sectrig pulse => secignore=255
- If there are multiple sectrig pulses, but in "same window" between primtrig missing teeth => secignore=255
- In rare cases, if there are multiple sectrig pulses, some coming every odd crankrot, some coming every even crankrot (should not be the case here with correct polarity... only an issue with wrong polarity when the offending pulse sometimes comes, sometimes not), then the sectrig pulse closest after primtrig missing tooth should be used (say normally 10 tooth after missing tooth), with secignore=13 any sectrig pulse after 13 primtrig tooth after missing tooth would be ignored (to prevent teeth from the other crankrot, say at 20 and 40 tooth to cause resync)
Please let me know if you have any ideas
trigger logs: http://www.vems.hu/files/Catalin_S50/
I manage to install another vr sensor ( crank sensor from a Maserati Quattroporte) it has 900ohm and seems that it works good. Only a sectrig bad flag right when the engine starts and when I rev from idle. This is with no filters.
Original sensor scopeshot:
Maserati sensor scopeshot:
Positive pulse should be followed by negative pulse (triggering happens at the zero-crossing negative-going edge), so these show Reverse polarity. Also, the amplitude of oscillations (child teeth ?) after the pulse are insane !
Is the large pulse appr 10 teeth after the primtrig missing tooth ? (if yes, than secignore=16, that is ignore sectrig after tooth22 could be useful)...
- The pulse in the trigger log is 9 teeth before primary missing tooth and camshaft full advance is 16 before
So the basic question remains:
- is the VR sensor currently installed with Reverse polarity, as shown by the above scopeshot ?
- If yes, why ? Does it need 360 deg rotation of ign and inj outputs, or just not run with correct polarity for some reason ? (or runs but with some problem, eg. misfire or trigger error ?)
- The sensor was always installed with right polarity, I think only in scopeshot is reversed because I tested on the sensor directly.
- Sectrig pulse would come slightly earlier with the correct polarity, but that should not be a problem ("measure tooth" can be adjusted if needed)
- Now if I change the polarity the signal is coming later and that tells me that now I have the polarity right? And I can not use it if it comes later because is on the second tooth after the missing tooth and when I advance the cam it will pass through missing tooth and from I heard is not good...
- If yes, why ? Does it need 360 deg rotation of ign and inj outputs, or just not run with correct polarity for some reason ? (or runs but with some problem, eg. misfire or trigger error ?)
- (fphil) poor Maserati QP ;) (do you have parts?). The VR pulse should be a simple sine (see my pages) and cleaner. I would scope the signal at Vems level but line not connected to Vems.
- I have Maserati in for some repairs and the sensor was not installed on the engine so I tested it on my car and bought a now one...
I was to the dyno a few days ago and tuned the engine. The vanos is working nice, the cam has very good response and is on target all the time...
The black graph is with the setup I had before and the red graph is with vanos, 100 octane pump gas and same boost.
Official is most powerful BMW in Romania :)
