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Has anyone been able to get the tach to work on a 24V conversion. We have coil packs and it appears that Phil thinks that we need to get a signal booster from Gotech to get the tach to work.

We were able to get the signal from one coil pack for a trail basis but since it only had one pulse rather than two it was not accurate RPM. We could not get it to work any other way. (Hopefully, I am wording this correctly since I did not personally test this)

The gotech shows a signal booster that you can buy and we just want to make sure this is the way to go before I purchase this.

Thanks for any suggestions.

GoTech has an RPM output - forgot which color wire. On the Milano this wire can simply be connected to the tach input (goes to the coil on a stock Milano) - this has worked for me on two separate cars. In some cases you do need the amplifier/booster. Just try hook it up without. If it works, it works. If not, get the booster.
Jes

There`s a simple little circuit you can build to get 3x signals form the 3 wasted spark coils..1N2006 diodes x3, 3x resistors and 3x Zener diodes for back emf..
The circuit can be downloaded from Haltech`s site..

One additional mod required on the back of the instrument is a 1 K ohm 1/4 watt pull up resistor between ground and signal.

Barry, I know squat about this subject but I watched Domingoes use a coil from a relay to make my rev counter work on race car.??You got my rev counter on my Haltech to work pretty easily on the 3.2.

Hi Barry,

Just getting around to the tach issue. Thank you very much for your information. The only other alternative that we heard is to purchase the boaster from Gotech since we do have a signal but it reads incorrect since it apears it is not compatable with our coil packs. Would you have a link to this circuit diagram?

Hi:
Were you able to get the tach working?
I'm tackling this currently - wondering which wire to snip and connect to the Gotech Ignition signal output wire?

Hi Michael,

We have not been able to get the tach to work yet. We need to get the booster for the signal. Phil will be doing this ASAP when I get the Alfa to him. I am planning to complete my check list of items with him this week and should have everything sorted within 60 more days.

Pity - are you going to go with the Gotech one?

http://www.gotech.co.za/catalog/product ... 1fb061e147

We are either going to get the gotech one or Phil will make the circuit that Barry is discussing above. We have not decided what way to go as of today but will let you know. What did you do for your speedo?

ar4me wrote:GoTech has an RPM output - forgot which color wire. On the Milano this wire can simply be connected to the tach input (goes to the coil on a stock Milano) - this has worked for me on two separate cars. In some cases you do need the amplifier/booster. Just try hook it up without. If it works, it works. If not, get the booster.
Jes

Hi Charles:

Did you try Jes' plan? Its possible that this might only work for the Milano I suppose.

One thing I'm not sure about is if the Gotech Tach output produces a single pulse per crank revolution - that would be my guess. If the GTV6 rev counter expects the same then it should work fine. If the GTV6 tach expects one pulse each time the coil fires, then the tach will under-read (really badly). Is this that you have seen?

Anyway, I decided to try it - will know if this was successful as soon as I can start the car. I just cut the old GTV6 signal input wire and in its place, fed it with the Gotech Tach output wire from the harness.
I will need to get the car running before I can verify that it works of course.

For speedo, I have a Milano Verde trans, with sender and amplifier and a speedo from an '86 GTV6. Similar to the tach issue, I have not been able to verify that this combo works...

Cheers,

Hi Michael,

My understanding is that it is under reading the RPM and this is why we need to boost the signal. I will double check with Phil tomorrow just to double check my understanding on this issue. I am going to run Jess's idea through Phil and I will let you know if we are successful. I also sent Phil the information on Barry's Circuit as another option.

We are addressing this issue currently so I will let you know ASAP.

Anything new with this one?

I'm working on a 3.0 24v conversion on my '86 GTV6 and will be using stock Motronic ECU from 166 3.0 V6. Anyone knows if the tacho works simply by connecting Motronics tach output to GTV6 tach?