67 dart stroker hellcat gen3 hemi with twin turbos...

turbofreek said
the sensor is ecu grounded and shielded. however i have spark plug wires in the general area but a solid 10+ inches away. ive got some plug wire shielding in my tool box. im gonna install after painting its bright *** yellow black with rubber coating. i pulled them further away and it runs smoother. so i know its at least an issues. however the power wires to the coils run parallel to the crank down the back of the block for about 2 feet. gonna try and sepwrate those as well. see if i get somewhere with that. i wonder as well id coil drivers can cause this as well. as they are at the hub of the ecu harness.

In reference to the coil drivers being a problem. Anything that is a very fast switched input or output can cause "noise". Some examples of switched outputs from the ECU is injector output and coil outputs, regardless if its low level out put such as the signal from the ECU or the output to the coil itself. These outputs are essentially turning on and off very quickly. If you were to look at them with an oscilloscope, it would be a square wave (on/off). Examples of switched inputs are VR and hall effect sensors. Just like they can have noise introduced to them, they can also introduce noise to other sensors/inputs. Hence the reason for the shielded cable. In my experience in the industrial/marine world, the safest I/O is milli-amp (mA) I/O because regardless of outside noise, the current still flows. Voltage sensors, such as the ones we have for water, and oil coolant and pressure, are prone to voltage drop problems (probably not on cars, but they can be problematic). I'm not sure why mA output sensors haven't made it over to the automotive world.