Updates on efforts to start my friend's T3 Sprint.
Installed my new battery in his car during testing to rule out low voltage.
Checked orange and yellow ignition trigger and fail feedback wires for continuity.
Checked coil brown/white and black/white coil to igniter wires for continuity and voltage for blk/white.
Checked distributor rotor and base timing at cylinder 1 TDC.
Did crank test check for voltage at igniter pins.
Friend's non running car: Igniter / Coil wire test results:
Black/White: 12V (+BAT Ignition on)
Brown/White: 12V (Coil - Ignition On)
Brown/White: 10V (Coil - Starter cranking)
Ground Connection: 0 ohms
Orange: 0.2 to 0.4V (Igniter Trigger signal from ECU while cranking)
Yellow: 5.2V (Igniter Feedback Fail signal to ECU while cranking)
We forgot to check if code 41 was still there after all this.
His engine still has no sign of wanting to start however.
Then, I took his currently installed ignition parts and spares home to my own running T3. I installed and tested his parts. The
results were the same regardless of my parts or my friend's parts used:
Testing involved 3 igniters, a T3 coil, spare G13A coil, 1991 T3 ECU, 1989 T3 ECU, all tested one at a time on my running T3 - resulted in normal engine start up in my car with a normal code 12 in Diagnostic mode.
T3tom's running T3 as a reference case:
Igniter / Coil wire test results:
Black/White: 12V (+BAT Ignition on)
Brown/White: 12V (Coil - Ignition On)
Brown/White: 10.5V (Coil - Starter cranking)
Ground Connection: 0 ohms
Orange: 0.1 to 0.7V (Igniter Trigger signal from ECU while cranking)
Yellow: 0.0V (Igniter Feedback Fail signal to ECU while cranking)
Orange: 0.7 V (Igniter Trigger signal from ECU while running)
Yellow: 1.0V (Igniter Feedback Fail signal to ECU while running)
Note: The voltage measures above from my reference car while the engine was running were obtained using a multi-meter. Ideally I should have used an oscilloscope to see what the waveform looked like. Guessing the signal voltage actually varied between 0-2 Volts.
My friend wants to replace the whole harness and start over but probably something simple was overlooked. Something in his yellow ignition fail feedback signal wire looks suspect. Do you have some other ideas? We may need to consider getting an oscilloscope for more tests if further wire by wire checking reveals nothing.
additional reference link to MK2 Turbo 3 Sprint full car wiring schematic:
https://www.imageupload.co.uk/images/201...Wiring.gif