Fiat Dino Forum (FDF)

Yes!

I have found the switch.

The cable for the tacho is hanging there. The tacho is connected to the terminal block on the coil instead. Any idea why is like that? The tacho works, but shows less rpm than real.

Thanks again.

If the tach is wired to the right [D] screw terminal on the red squarish ballast resistor then the wiring is ok.

If it shows less RPM than you actually have then it requires a recalibration, which can be done by a speedo shop. You can also do it on your own if you have access to a square wave generator and am willing to disassemble the tach.

Are you running in Normale or Emergenza mode? If all is fine you should be able to hear a humming sound around 280 Hz coming from the Dinoplex after switching on the ignition,

I have access to an oscilloscope, I can borrow it from work. If you tell me how to do it, I think I will have no problems.

I was surprised the first time I switched the contact on. Yes, it whines.. I'm running in normale, still haven't checked emergenza mode. I know it has to be done with engine stopped and contact off. I'm doing some work on the vacuum lines, and I'm waiting for engine spares before I try a correct tune. i will try when engine is finished..

Thanks..

By the way, can I connect the tacho where it was supposed to be?

You need a square wave generator, which is set to 250 HZ and an output voltage of 0-10V. Connect the generator output to ground and the tacho input, and supply 12V to the tacho. Now gently turn the trimmer/potentiometer on the tacho circuit board until the tacho displays 5000 RPM. Let it run for five to ten minutes and readjust if necessary.

You can connect the tacho to the original wiring, which is the wire #4 coming from the Dinoplex enclosure as in the middle diagram of the link i sent you.

Good luck,
Adrian

Voltage 0-10, whatever it is?

Thanks..

The square wave signal output from the frequency generator should have an amplitude of zero to 10 volts, e.g. the output voltage should be around 10 volts.

Adrian, a question you'll might be able to help me out with.

About distributors, i read at Ferrarichat a tread from you about optimized advance curve for 246.
http://www.ferrarichat.com/forum/206-24 ... 246gt.html
It looks a bit drastic compared to the original advance curve, but now that i have the possibility to tune my advance curve i would like to know whether it is really safe to program your advance curve. Do you still, when possible, program (or adjust) the advance curve like the one it that tread?
Did you really test until the point of engine knock uccured?

alh wrote:The square wave signal output from the frequency generator should have an amplitude of zero to 10 volts, e.g. the output voltage should be around 10 volts.

Understood. Thanks.