tach trouble
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The tach info comes from the ignition module in the distributor, goes through a tach filter and into the dash cluster. The microprocessor in the cluster measures the time between pulses and calculates the RPM from that. The microprocessor controls the display of RPM, both the segmented RPM curve and the digits.
The tach wire is the tan wire connected to the distributor cap. The tach filter is mounted on a bell housing bolt on the driver's side. It's the black cylinder with the metal clamp around it under the oil pressure sender in this pic (my tan wire got pretty messed up when I had a fire in my engine -- fuel pressure regulator diaphragm ruptured):
The tach wire is the tan wire connected to the distributor cap. The tach filter is mounted on a bell housing bolt on the driver's side. It's the black cylinder with the metal clamp around it under the oil pressure sender in this pic (my tan wire got pretty messed up when I had a fire in my engine -- fuel pressure regulator diaphragm ruptured):
