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Subaru v1-2 wrx2+ ecu trigger issues.

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Hi.....Id really appreciate some help I'm having problems with my link wrx2+ plug in ecu, mainly the trigger offset.

I'll start by giving car spec:

  • Ej207 block fully forged ej25 crank and stroker pistons. 
  • v4 STI heads
  • 1000cc injectors, currently running walbro 255 pump
  • Borg warner 6758 turbo
  • Subaru 6/7 trigger 
  • Impreza v7 Coil on Plug upgrade. (uses previously trigger pulse directly from ecu instead of old set up with separate ign driver and coils.
  • water to air chargecooler.

The set up was running well on megasquirt (DIYPNP) but i decided to upgrade to link g4+. I built the megasquirt to directly interface with the cars wiring harness.

I installed the link ecu into the car and made a few changes:

  • I don't use a MAF anymore so i decided to use the An2 volt input as the air temp input. A 1k resistor has been installed in a potential divider network with the air temp sensor. In and working. Cal table set to the sensors values.
  • I have a GM map sensor that was sold to me as a 3 bar but only calibrates as a 2.5 bar. I will probably move to using a genuine Bosch sensor as it there is more chance of getting a genuine product. I ran the cal and it zeroed.
  • I converted the narrow band o2 to wideband input.
  • All dead times set for injectors 
  • turned the master fuel down as i expected it to flood if i used the base maps figures. Fuel and ignition table left alone.
  • Followed full set up procedure in manual provided.
  • checked corresponding coil and injector outputs
  • turned the fuel injection off for calibration

So......the tricky bit. I went to run the the trigger calibration at 0 degrees (as recommended) ref set to 10 degrees. Usual cut plug lead in coil trick with timing light clipped on. The timing light started flashing erratically on turn over and the spark was erratic also. When you stop cranking it sparks two or three times (basically anywhere at any time it likes). Eventually the only offset that i could get a near stable spark and TDC reference out of was 320 degrees btdc. After setting this figure I thought it may run but not even a kick, i tried 360 degrees away from this figure (-40) and the timing light will flash there, I also tried multiples within +- 360. I have got the car the to fire at 345 degrees but it runs like the coils are wired up wrong and often pops and bangs.

I have done a full pin out of harness replaced crank and cam sensors checked supplies etc! I tried the megasquirt back on the car and it will start, I've tried the standard Subaru ecu and it provides a stable spark as its attempting to start the car, to be honest it provides the strongest switching signal of all of them! The link provides a 7.2V max pulse to activate the coil amp and the Subaru provides near battery voltage as observed on an oscilloscope.

I scoped the crank and cam pulses externally and using the link software I have attached screenshots to this article. They both seem strong and stable enough for the ecu to interpret. I have had a play with trigger thresholds and filters also but no luck.

Like I say other ecus will work so I'm at a bit of a loss to be honest. Maybe someone has had this problem before?











running 345 base.jpg

turn over 0 deg.jpg

turn over wrx2.jpg

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Trig one signal is inverted. The wiring of crank sensor needs to be swapped over.

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On 5/10/2019 at 12:51 AM, Simon said:

Cam is fine, Swap at the sensor plug.

Hi Simon it worked and I got the car started.

I've included 2 screenshots below if anyone else has the same issue mine has been brought about by putting new conduit on my wiring and not paying attention to where the wires go!

Screenshot titled: "Crank wires swap.jpg" is correct

Screenshot titled: "turn over 0 deg.jpg" is wrong

Thanks again Simon/Link I would probably still be burning my starter out now without this advice! 


crank wires swap.jpg

turn over 0 deg.jpg

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