Hello,

Changed valve cover today and accidentally over torqued the ground bolt and snapped it. Car won't start now tried to ground directly to the case and to no effect.

Not sure if I blew the ecu?

 

I seem to recall that ground is needed for the coils to fire. I also recall something, possibly shorting out if it is not grounded.

 

The ground is required for the coils to fire since it's the ground path for the coil primary circuit, but you won't damage the ECU if it's not connected; if it's not connected, there's no current flow in the coil primary; if there's no current flow in the coil primary, the secondary will never fire.

The ground is X64561.



Here it is in the schematic (see red arrows)



The yellow (coil 3), white (coil 1), blue (coil 2), and orange (coil 4) are the ground-side switched wires from the DME (engine computer). The green wire is the system voltage from the DME.

Did you remember to plug in both the inlet and exhaust camshaft position sensors? Those connections are on the valve cover, and the engine won't start without a camshaft signal.