1990 VW Golf GTI Digifant II


16VT’s involvement: Wired in fully functional plug and play Megasquirt ECU; calibrated fuel, ignition and idle.

Chassis: stock;

Forced induction: none.

Engine: 1800cc, RV engine code, 8valve, stock.

Injection: Port injection, 185cc/min  highZ injectors, Bosch coolant and Bosch intake temp sensors.

Description:  The objective was to replace the limited Digifant 2 system with the megasquirt. A suitable adapter was made to link the megasquirt to the digifant 2 loom. All stock sensors were used. Megasquirt v2.2 PCB was utilised.

Pin configuration:

MS GROUNDS (8,9,10,11,12,13) go to T25/13, T25/19
MS SENSOR GROUND (19) goes to T25/6
MS MAT (20) goes to T25/9
MS CLT (21) goes to T25/10
MS TPS SIGNAL (22) wired externally
goes to T25/2 (and also tee-ed in cabin to blue wire)
MS PIN 24 goes to T25/8 (hall sensor 12V supply via internal megasquirt jumper)
MS PIN 25 goes to T25/18 (hall sensor signal to 4N25 via XG1)
MS TPS Vref (26) goes to T25/11 (red/blue)
MS +12V (28 ) goes to T25/14
MS FIDLE (30) goes to T25/23
MS INJ1 (32,33) goes to T25/12
MS INJ2 (34,35) wired externally (green)
MS X14 (31) goes to T25/25 (coil)
MS FUEL PUMP (37) goes to T25/3

Pin 1 of Bosch ignition module must be jumpered to pin 6 if a VB921 is to be used.
T25/22 needed to see 12V (jumpered to T25/14) for ISV power supply

pin 27 is externally brought out as a yellow wire

pin 29 is externally brought out as a white wire