Misfire indications

[Fastbird]

Just wondering, does the Tach get it's signal from the coil wiring?? Reason I ask is because I got on the car hard this morning and the tach was jumpy at points. Figure it's just a spurious signal coming from the coils.

Thank you please drive through.

 

[l-m tech]

does the car feel like its cutting out when the tach acts up.any cel.

 

[Fastbird]

Nah, not really. But I could easily see it being just a momentary thing that would be rather unnoticable too.

 

[l-m tech]

shorting coils do cause a lot of strange things to happen. voltage spikes in the ignision system are makig the module act up to. i think the tach get its input from the pcm and the pcm gets its info from the crank sensor.