Direct coil pack diagram
- Thread starter Zach
- Start date
No start situation, or intermittent start, not firing ignition or fuel injectors properly. before it would start and die over 15 - 30 seconds, then sometimes it would just start firing the fuel injectors with the ignition on and engine off. I got some serious gremlins going on. I sent you my logs a year or so ago and you thought the ecu was defective but I shipped it to you and you said it was fine. My guess is intermittent voltage to some part of the ignition circuit, causing the initial fuel pump and injector prime to keep repeating or sometimes no power at all and occasionally enough power to actually start.
That doesn't 'seem' like ignition. I think I would focus on the power issue.
You said it sometimes does the fuel pump reprime on its own, is that with engine off? That would indicate the ECU is being reset.
Can you turn the key on and start wiggling wires at the ECU?
There are two 12v supplies to the ECU, one is from ignition (A6 at ECU), and the other from the battery (C16 at ECU). I would wiggle those. I would also be tempted to make temporary wires directly to the battery to see if that fixes it.
I'm not sure what you have already tried.
Also, make sure all original grounds from ECU to engine are good.
You said it sometimes does the fuel pump reprime on its own, is that with engine off? That would indicate the ECU is being reset.
Can you turn the key on and start wiggling wires at the ECU?
There are two 12v supplies to the ECU, one is from ignition (A6 at ECU), and the other from the battery (C16 at ECU). I would wiggle those. I would also be tempted to make temporary wires directly to the battery to see if that fixes it.
I'm not sure what you have already tried.
Also, make sure all original grounds from ECU to engine are good.