Tach issues...

[92conv]

I was having some issues on my '92 with the tachometer spiking as high as it would go when I would go to start it up and it would remain max'd for the first few minutes. Crazy thing is, while it was pegged I would step on the gas and it would rev down which is the complete opposite of what it should do. Funny stuff really. Now it wouldn't do it all the time but it was doing it quite a few times. I am going to hit the books on this in the morning but thought I would throw it out there to see if anyone has an opinion. Where does the tach get it's signals from? ECM maybe??? My babys not running right now and I think that might have been an indicator. By the way...the totally rocks!!!

 

[Hrtbeat1]

Not sure about the LT1 but the L98 cars have a tach adapter mounted ont the lower firewall near the tranny. The signal comes from the distributor then thru the filter to the tach display. Mine was doing nearly the same thing and I found the tach adapter was bad.

On the LT1 there should be a module coming from the optispark maybe near the left front fuel injector.

Hope this helps.