Where does the tach get its input?

[Noobie]

Hey all... where and how does the tach get it's input?

Where and how does the gas consumption gauge get it's input?

Anybody know?

[Noobie]

A user on "the other board" indicated that the gas consumption gauge is vacuum driven.

Still don't know where the tach input comes from. Can anybody help?

[DaveClement]

I believe that they both read off the computer module(s). One for the V8 and two for the V12. There is probably no good way to tap into them.

On a V12 you could probably tap into the ignition coil to drive a conventional aftermarket tachometer. Each side of the engine is managed as a separate 6 cylinder engine with a conventional ignition coil and distributor. The V8 has separate ignition coils mounted to each spark plug and no distributor, so you’d have trouble finding somewhere to tap in.

The question in my mind is why?

[Noobie]

I'm trying to diagnose the weird problem I had the other day - the engine seemed to stop responding, but the tach stayed at 2K even though I was throttling up/down. The fuel consumption gauge still seemed to be responding to throttle, so I'm wondering where the inputs for the two gauges come from - and why one might be responding and the other not responding.

Make sense?

[Jfstu]

Thats peculiar. Is the M62 throttle by wire?