by MFaulks » Sun Jul 15, 2012 11:10 am
Well I wrote a long post for you and lost the whole thing, on my phone...
So quick version:
Disconnect ecu, take loom end connector, take each pin in turn and buzz out with a dvm on resistance / continuity all the other pins. Make sure you get correct resistance readings for the pin pairs - sensors etc. Make sure the air temp and water temp read in the right ball park. Check for shorts to ground where there shouldn't be, open circuits, and finally continuity between lines that shouldn't (usually as a result of ageing and cracking insulation - injector lines are bad for this). Re check your tdc as well.
Assuming all good, then connect ecu back up, switch to ignition on, and then go round all the sensor (air and water temp, 02), tb pot, map, tdc lines (signals and both power) with a dvm I'm Vdc and measure to chassis / engine 0v. The pot, and sensor 0v return lines are not true 0v, but up on a small pedestal voltage to reduce noise susceptibility. Check this is the case, if not you have a short on the ecu sensor 0v rail. Please report these values back. Check the pot swings approx 0.25Vdc to 4.5Vdcmin on the wiper, note this measurement is against the pot 0v line not chassis for the reason above. Let me know how you get on.
Check loom continuity between the pack connector and the ecu as above.
Do you have a spare ignition unit?