Hey,
I went to dyno my car and they connected their dyno to my RPM test connector at the driver's side under the hood. For some reason, their measurements were all over the place at higher rpms. My rpms measure fine on my dashboard tach. The helms manual shows the blue test wire to come from the distributor's ignition control module directly. What could be the problem? Have other's used this wire without problems?

thanks!

 

that's the wire.

a lot of ppl actually use that wire to control their aftermarket tach's.