Hi everyone,

i've been noticing lately that on cold mornings when i first start up my tach is showing about 200 rpms after a couple of minutes warming up but the engine sounds like its running normally. today i really realized something was wrong because the tach read 0 rpm. After driving for a while the tach starts to work normally again. What could be causing this? is the tach dependent on the output from the ignition coil?

thanks

 

yes I do believe so (somebody correct me if I am wrong). When I had my remote starter installed they hooked up the tach pickup wire to one of the wires comming out of the coil. Somebody probably has a pic or knows which one. I am stuck @ work so I can't look right now

 

My tach will run fast and slow sometimes, by 500-2000rpm, so I am interested in knowing also.

 

mines is doing the same please chime in.

 

Mine runs about 2x over actual rpms. I'd really appreciate it if someone here can chime in with some info on the pick up point for the tach. I'm thinking mine is connected in the wrong place.

 

kind of an old post but any ideas??? on what could be causing this

 

the tach signal comes from the ignitor. should be the same as the coil negative (-) terminal.
but if the tach itself is malfunctioning, it could place an abnormal impedance on that terminal and not read correctly, and also cause the engine to not run properly.

 

Old thread, but here's the tach wiring for my '95 3.0

 

mine runs fine i just noticed that the tach was acting funny like reading 0 and the motor was idleing fine, i also noticed the tach jump 500rpms then a min later it droped back down