s50 no spark

[bonobo]

Hey guys, my car cranks awesome, but I can't seem to get spark. I am getting fuel in the fuel rail. Used coils with 40k on them (supposedly), new spark plugs, 413 red label DME. I just replaced 02 heater relay, fuel pump relay, and DME relay. Also replaced crank position sensor. I went through the strut ground, engine ground (I'm using two) and injector harness grounds and cleaned them with a wire wheel. When key is in on position, ICV hums, but DME relay vibrates and makes loud buzzing noises. Also for some reason the tach wobbles around 3k, without me cranking the car.
Is anyone noticing something that I don't? I really want to drive my car, it's been out of commission for way too long.

[e30rapidic]

charge the battery fully and try again...seriously.

[bonobo]

charge the battery fully and try again...seriously.

Already did that. Thanks though.

I also noticed that the DME relay only vibrates and buzzes when the DME case itself is not grounded to the strut tower. When the case is moved elsewhere, the DME stops buzzing and the DME relay starts. This is all very weird to me because I cleaned up and double checked the harness ground before I installed it.

[pandaboo911]

Same exact thing happened to me when I touched the ECU case to 12v for a second.
The ecu was toast, I swapped in another 413 red label and the buzzing stopped. I figure it was an internal short in the ECU

The buzzing is an indicator of a short to ground, the magnetic coil in the relay is continually loading up and discharging very fast, making that buzzing noise. Either your ECU is shorted, or wiring related to the ECU is shorted.

consider testing with a known working ECU. The ecu case is supposed to be grounded internally, should not require the case to be grounded.

[e30rapidic]

The ecu case is supposed to be grounded internally, should not require the case to be grounded.

true but a lot of people have issues if the ecu itself is not grounded.

[bonobo]

Same exact thing happened to me when I touched the ECU case to 12v for a second.
The ecu was toast, I swapped in another 413 red label and the buzzing stopped. I figure it was an internal short in the ECU

The buzzing is an indicator of a short to ground, the magnetic coil in the relay is continually loading up and discharging very fast, making that buzzing noise. Either your ECU is shorted, or wiring related to the ECU is shorted.

consider testing with a known working ECU. The ecu case is supposed to be grounded internally, should not require the case to be grounded.

Awesome thank you, I have a new dme on the way so I'll try to rule that out this weekend.

Sent from my SPH-D710VMUB using Tapatalk 2

[bonobo]

Awesome thank you, I have a new dme on the way so I'll try to rule that out this weekend.

Sent from my SPH-D710VMUB using Tapatalk 2

It was the DME.. scared the shit out of me when it fired up. Thanks guys!

[agent]

Nice call pandaboo911!