In reply to a question posed by member Aspec, regarding the improved grounding I mentioned in a recent thread:
The igniter electronics are potted. A ground strap exits the encapsulation and connects to a screw inside the top case. The lower case is screwed to the top case and then bolted to the car's body leaving several places for corrosion to effect the ground path. Because this path serves as the ground for all of the igniter's circuitry, including the coil drivers, I've seen two cases where it caused slight misfire that was only visible using an ignition scope.
Improvement involves splitting the cases and connecting a wire directly to the internal ground screw then running it out through one of the open vent holes in the case. Run the wire to the nearby negative battery body ground cable. Use a quality single point connector in the wire if you like so as to make igniter removal easier. I don't though. Finally, clean the upper and lower cases and mounting bracket to retain the original path as a back up.
When you bring that wire out you can daisy chain it to the ECU grounds on the manifold. That way they also end up going directly to battery negative. Since the manifold grounds are the only ones in the car not redundant doing this provides a solid electrical path back to the battery.
Another ground improvement is for the O2 sensor. It's ground path is through the turbo elbow, turbo, and exhaust manifold. Not exactly a good way to do things, especially when dealing with the tiny signal level put out by lambda sensors. It's why modern ones are usually four wire. Correct this by running a wire from one of the sensor's mounting studs to the existing nearby ground wire that runs from the firewall to the head. For heat protection run it through a small diameter length of silicone vacuum tubing or use the silicone/fiberglass sheathing found on the O2 sensor wiring. You can get that stuff from several places, McMaster Carr for example.
The igniter electronics are potted. A ground strap exits the encapsulation and connects to a screw inside the top case. The lower case is screwed to the top case and then bolted to the car's body leaving several places for corrosion to effect the ground path. Because this path serves as the ground for all of the igniter's circuitry, including the coil drivers, I've seen two cases where it caused slight misfire that was only visible using an ignition scope.
Improvement involves splitting the cases and connecting a wire directly to the internal ground screw then running it out through one of the open vent holes in the case. Run the wire to the nearby negative battery body ground cable. Use a quality single point connector in the wire if you like so as to make igniter removal easier. I don't though. Finally, clean the upper and lower cases and mounting bracket to retain the original path as a back up.
When you bring that wire out you can daisy chain it to the ECU grounds on the manifold. That way they also end up going directly to battery negative. Since the manifold grounds are the only ones in the car not redundant doing this provides a solid electrical path back to the battery.
Another ground improvement is for the O2 sensor. It's ground path is through the turbo elbow, turbo, and exhaust manifold. Not exactly a good way to do things, especially when dealing with the tiny signal level put out by lambda sensors. It's why modern ones are usually four wire. Correct this by running a wire from one of the sensor's mounting studs to the existing nearby ground wire that runs from the firewall to the head. For heat protection run it through a small diameter length of silicone vacuum tubing or use the silicone/fiberglass sheathing found on the O2 sensor wiring. You can get that stuff from several places, McMaster Carr for example.
