knockbox monitoring EA82T flapper afm

CONTROL V'd from my subaruxt post

Wondering if anyone else has done what I have to monitor the test socket below the coil of 85 86 flapper style ??? Starting to think no XT came out with first gen EA82T with flapper style afm and the 3 plug ECU though - refering to my 85 sedan. I have temporarily used a multimeter just taped to the dash, now fitted a voltage readout unit from ebay that is capable of reading the 1.7 to 4.5 V range for this task.

Does anyone know if/where any XT4 has a socket to test same ?

I have had multimeter under bonnet with tiing light hooked up, engine running and tapped block with solid extension bar and saw the DMM go from 1.7 V - normal operation to 4.5V when the timing is suddenly pulled back from 20 down to 10 DBTDC and with no further mischievous knocking, timing steps back to 20DBTDC.

I have been running this for a month now and never seen the Volts change under load, even with a 250kg trailer hooked up and loaded up with a few hundred more kilos. Thinking the LPG is pretty good for turbo with its suggested RON (AUS) of 109