Well, no luck today, and we've gone as far as some bits of wire and croc clips will get us (ok and my mates tester, and not forgetting the trusty old bulb).
It's still confusing, I followed the diagnostics from the workshop manual Graham sent (thanks Graham..) and we still couldn't suss it.
One thing for sure is that the fuel pump is OK, as we powered direct from the battery to its relay. However the carrier for its relay doesn't seem to be earthing. When we earthed the relay seperatley the pump powered up, but we still had no spark.
We followed page 30, section 29 'No Power to System' All the ECU pins were correctly powered or earthed, except pin 56 which had no power. We followed the instructions which led us to 'restore wiring' in Test B15, page 29-31. this is an earth. We earthed the relay pin seperately for this and the fuel pump relay, but still no spark.
We tested the TDC sensor, although we were guessing on which terminal to stick the tester into (except black/earth). One reading was 0.8 (assumes correct as under 1), the other was 3.6. I'm still not sure that this is OK or not, does anyone know for sure if a duff TDC sensor will disable both fuel and ignition?
So, in summary, we have power to the relays, but seemingly no earth to the relays, and no power to Pin 56 on the ECU, Is my ECU buggered?
Also, the self diagnostics no longer works, the injector light refuses to flash any more. And, on page 29-21, it lists the relays, but this must be for a 16v, as mine seemed to be in a different order. From left to right on the V6 we had
Fuel Pump (S12a), Ignition (S12b) and Aux (S12d). This had to be so as when we powered direct to the left hand relay s12a (when looking at them) the fuel pump primed.
Howard - are you aware of any work that might have been done previously, as someone has marked the relays with red pen, plus the 15a fuse which is for the fuel pump isn't in front of the fuel pump relay (which shouldn't matter, but logically it ought to be).
Unless anyone can offer some more advice it looks like I'm going to have to tow it to a specialist to get the ECU and TDC sensor checked properly. Have I missed something obvious?
Thanks to everyone that responded before....Tim