2018-02-13:
Whas this trigger found to be fully working?
I have a Audi ABH enginge in need of VEMS.
I need definitive answer this trigger will work.
I already have a VEMS V3.8 ECU with auditrigger/camhall inverter (suitable for VR/VR and VR/auditrigger)
Installing Audi 4.2 Liter V8 ABH code engine.
Ignition: MembersPage/Norbitron/AudiV/IgnitionTransformers
- summary: Old HV wire rubber insulation failed => caused Trigger error
- engine works well again with good HV wire
- thanks for following instructions and detailed report
- engine works well again with good HV wire
The engine has Auditrigger (every 2nd sectrig VR pulse masked by cam-HALL) like Audi AAN.
- Primary (VR)trigger, RPM sensor are sensing 136 yes 136 teeth on starter ring
- Secondary (VR) trigger are sensing the TDC point. 72° before TDC.
- Camshaft HALL window for masking sectrig. 1 small window wheel (short 0V and long 5V ?), like on 3B or AAN.
- note: this is NOT the same as "third trigger" (third and fourth and fifth triggers are connected to specific inputs)
- so avoid "3 trigger" naming because that is reserved for real 3 trigger setup which VEMS also supports (with variable camshafts; Upto 4 variable camshafts and 5 triggers).
c272: 272 teeth on full engine cycle, so 34 tooth between events:
- divider=17, number of teeth on wheel=16 ; next trigger tooth=2 (I would use this "divby17": after the divider, setup is similar to c016 : 16 primtrig pulses for 1 sectrig pulse)
- reftooth sequence steps by 2 each time: 0 2 4 6 8 a c e
- this setup is very similar to the c270 (135 tooth) with divby27 which has been benchtested beyond 14000 RPM
- divider=2, next trigger tooth=17
- number of teeth on wheel=136 (might or might not work: >128 so it might internally mis-state as "resync").
- Only try divby2 as "last resort".
Can this trigger setting work?
http://www.vems.hu/files/Norbitron/v8trigger.vemscfg
Will check your annotated vemslog.
Triggerlog hint:
Please publish triggerlog (obviously that is the way to proceed during trigger setup (even when it goes smooth without issue).
When capturing triggerlog, if configured for auditrigger, some pulses might be hided.
- so if not starting anyway, and capturing triggerlog at cranking RPM (<200), maybe a good idea to cheat, and configure normal (eg. 60-2 or coil type without divider) trigger to see events
- eg if one tooth is broken and causing problems (it happened before), that might be very good to see
- do not save that "triggerlog cheat config", or save with very characteristic name (so you and whoever helps you know that config was only used for triggerlog, not for startup attempts !)
- and do not forget to configure auditrigger + divider after triggerlogging.
Old HV wire rubber insulation failed => Trigger error
The engine started up with VEMS, and worked fine for 2 weeks.
2017-06-03 (without doing anything special) I was driving on highway at 3200 RPM when I feel some missfire, the engine was shaking. Connected my laptop (VemsTune) I saw trigger error
(which might be the cause, or RESULT of ignition problem: confirmed, fixed after swapping the faulty HV wire).
Please verify config (with the one saved when all was good)
- and verify firmware (yes).
- If all good (since the trigger looks quite good, thanks for taking notes !),
- it is most likely some ignition misfire => trigger interference: confirmed, indeed it was HV wire insulation failure.
On lower RPMs there wasn't missfire/trigger error. Outside temp about +30deg. When i came back home at night (+12-15deg)the missfires came at about 2500rpm. And now comes randomly RPMs (even idle ?).
My measurements:
- EC36/27 voltage with connected ecu/ign on=0.2V , At idle=0.34V, resistance between EC36/27 and EC36/26 = 1160ohm when ECU connected, disconnected ECU connector=1212 Ohm, Sensor resistance= 1210 Ohm
- good, normal values, but still, connect a 27k..47k pullup resistor between EC36/27 and +5V (this results in "stronger pullup", resulting in 0.3 .. 0.4V DC bias, and more noise tolerance, although still might not tolerate ignition related pulses)
- EC18/12 voltage with connected ecu/ign on=0.0V , at idle=0.22V, resistance between EC18/12.EC36/26 = 548ohm when ECU connected,disconnected ECU connector=1216, Sensor resistance =1215Ohm
- EC36/13 voltage = 4.1V, on idle = 3.8-4.0V
Scope measurements:
- 3 trigger
3 trigger lower resulotion
3trigger on idle
Primary and secondary trigger on idle
Secondary and HALL trigger on idle.
Triggerlog with undivided settings:
http://www.vems.hu/files/Norbitron/V8t/scope/undivided.triggerlog
Triggerlog when trigger error visible. I don't know what is the actually rpm:
http://www.vems.hu/files/Norbitron/V8t/scope/triggererror.triggerlog
I sent an url with vemslog.
Here is a slow acceleration in 4th speed then enginebraking. You can see the trigger error when i accelerate and also with engine brake when fuel is off.
The VE and IGN tables aren't 100% yet.