Until recently my MPI was fitted with a SC Injection Kit, The car was running, but was very rough, running very rich and was a bit of a dog, Despite trips to a number of tuners no one could get it running as I would like.
In desperation, I made the decision to revert to the Rover set up. I bought an ECM off eBay (to replace original defunct ECM) and sent it away to have it checked over and have the immobiliser function removed. The ECM came back with a clean bill of health.
Having fitted the Rover set up the car will not start. I believe that the MEMS Relay is not energising. The Workshop Manual states the following:
MEMS ECM
The ignition sense of the ECM receives battery voltage from fuse A4 in the
passenger compartment fuse box on a W wire provided the starter switch is in
position II. As a result the ECM supplies an earth from the main relay control on
a WK wire to one side of the main relay coil (within the MEMS relay module).
Since the other side of the main relay receives battery voltage on an N wire from
link 4 in the engine compartment fuse box, the relay will energise switching
battery voltage via the relay contacts on an NK wire to the injector(s), purge
valve, stepper motor, ignition coil, manifold heater (Japan only) and positive feed
to the ECM.
The ignition sense on the ECM receives 12 volts, however, I do not believe that the ECM is providing an earth to the main relay in the Relay Module. I have continuity on the WK wire.
How can I test that the main relay coil is receiving an earth? from the ECM?
If the ECM is not providing an earth, why?
I have an old MEMS Relay module that I have opened up. By manually operating the various relays I can get the engine turning over, fuel pumping, and a spark, which suggests to me that the ECM is not controlling the various functions?
Please keep answers to the basics, electrics frighten me at the best of times and, at the moment my brain is in meltdown.
Please, no one suggest that I revert to the SC Injection Kit, I might just cry!