MembersPage/MarcellGal/EngineSwap/VrTrigger (2006-03-16 04:43:08)

InputTrigger related page for MembersPage/MarcellGal/EngineSwap

The output side is explained on MembersPage/MarcellGal/EngineSwap/Ignition


Sloppy VR mounting problem - gone

The gap between 60-2 crankwheel and VR sensor (with the home-made adapter) was originally a bit too big. At cranking the signal (low amplitude because of low RPM) was susceptible to noise.

Since the gap had been made reasonable, it start OK.


Signal quality and polarity - VR fixed

After hooking up LEDs and notebook soundcard it became obvious that trigger syncron is lost soon after it would fire up (ign and inj output not activated for some periods).

Even though MegaTune logs revealed that there were no resets, GND5 turned out to be very weak (and clearly interfered with GND through internal protecting diodes that I used between GND and GND5). 3 powerful 1mm2 wires used for GND5 fixed it.

With mde40 logging (see InputTrigger/TriggerLog) it became obvious immediately that trigger signal was reversed. Instead of one 3x long pulse (60-2 wheel) there were 2 longer teeth (appr. 1.5 .. 2x long). We connected it according to the documentation (neglecting the result of simple but effective "hammer" test). Confusingly, usually there was trigger signal, it was just unstable and lotsof wheel-errs showed up (eg. on LCD).


Runout - InputTrigger/RunOut

I could reproduce the runout very easily on the table (I got a flue anyway incar testing ain't work). I hooked up LEDs to injection and ignition outputs.

After playing with mstBA (60-2 toothwheel OutputTrigger) and msp01 .. msp06 (mostly msq00) I noticed that ignition and injection LEDs flash unevenly. There are full crankrotations left out. This is typical for loss of inputtrigger signal. I hooked up a soundcard to check signal with audacity and saw that signal amplitude is significantly lower for the first tooth after missing tooth. So I inverted the stimulator output from 40 => 80:

so after the missing tooth it starts with a (neglected) rising pulse, than comes the (used) falling pulse.

I could discover the same pattern in the sound recording of the real VR log, and LED flashing in the car behaved in a similar way.

I'll have to patch the LM1815 circuit with the resistor that lowers the adaptive threshold (or jumper to nonadaptive mode).


Position - solved

I didn't have time to hook up and log the factory ECM, but the changed block changed position anyway.

The way it was found

After a good start from photos (see below), I just simply sweeped through the tdc_delay using the directly attached keyboard. It's very easy to do so :-) Apparently best results:


See also