1995 Opel Calibra C20XE Motronic 2.8


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

Chassis: stock;

Forced induction: none.

Engine: 2000cc, C20XE engine code, 16 valve,stock.

Injection: : Port injection, 151cc/min injectors, Motronic 2.8 wiring harness, 60-2 trigger wheel, VR crank sensor, PWM 3-wire bosch idle valve, Bosch coolant and intake temp sensors, 2 coils in wastespark mode driven by external Bosch ignition module;

Description: The objective of this install was to use the original wiring loom. To do this, an old 55 pin Motronic ECU was cannibalised and turned into an adapter. The MS was installed inside the car, with wires running to the 'ECU' box. All the original sensors and actuators were used, including the air temp sensor integral to the air flow meter.

A v3 PCB was used, with some additions including a TIP122 for PWM idle control, an IRLZ44 for boost control, 2 VB921's for waste-spark capability, and a few BC337 transistors for some 'extras'. The 3-wire ISV of the car was held closed by grounding one of its pins via a 39ohm 50W resistor..

Pin configuration:

goes to T55/25 to ground it at WOT for AC compressor to switch off  (pink)
MS VR- CRANK SENSOR SIGNAL (7) goes to T55/48 (pin 2 of VR sensor) (green)
MS GROUNDS (8,9,10,11,12,13) go to T55/42, T55/14, T55/24 (black)
MS SENSOR GROUND (19) goes to T55/19, T55/30, T55/10 (black)
MS MAT (20) goes to T55/44 (black/red)
MS CLT (21) goes to T55/45 (yellow)
MS TPS SIGNAL (22) goes to T55/53 (blue)
MS O2 SENSOR SIGNAL (23, brown) goes to T55/28 (blue)
MS VR+ CRANK SENSOR SIGNAL (24) goes to T55/49 (pin 1 of VR sensor) (white)
MS SPARE PIN (25)  goes to T55/20 to drive coil B (brown)
MS TPS Vref (26) goes to T55/12 (white)
MS +12V (28 ) goes to T55/27 (red)
MS SPARE PIN (29) goes to T55/43 (to drive TTL cluster tachometer)  (white)
MS FIDLE (30) goes to T55/4 (yellow)
MS INJ1 (32,33) goes to T55/17 & T55/34 (yellow)
MS INJ2 (34,35) goes to T55/16 & T55/35 (green)
MS coil A control (36) goes to T55/1 (brown)
MS FUEL PUMP (37) goes to T55/3 (FP relay) (green)
T55/46 (relay module) needs to see ground when ignition is turned on, and to do this a relay is wired in using the ignition (T55/27) line and a ground somewhere, the objective being for the relay to ground T55/46 when it is triggered by T55/27.

The 'extras':

Launch control, JS11 - SPR1, pin 3 (yellow)
Shift light CPU10, JS7 - SPR2, pin 4 (white) (can be routed to T55/22  to convert the check engine light into a shift light)
Switchable maps, SPR3, pin 5 (blue)
Output 1  SPR4, pin 6
(to disable AC compressor at WOT)
Coil B IAC1A, pin 25 
Boost, JS2 - IAC1B, pin 27 (blue)  goes to T55/5 (uses evap canister for boost solenoid)
Tacho out, JS1 - IAC2A, pin 29
Output2, JS3 - IAC2B, pin 31 (red) 

To bypass the OEM module, jumper pin 2 to 1 and 6 to 7.

To disconnect AC compressor at WOT, T55/25 needs grounding when TPS is near WOT. (pin 6 used)