1ggte tacho source

[turmite]

Once again in need of info, Ive got a ra 60 1g conversion, engineered the lot except for the tacho source wire...Ive had the original dash updated for the 6 cylinder but cant seem to get the tacho working properly. The tacho works fine up to 4000rpm and then stops so I suspect the wiring on the engine end is incorrect...can anybody tell me exactly where to source this wire eg Igniter The donk is a gen 3 if that helps.
Ta once again Geoff

[JustCallMeOrlando]

Where are you taking the tacho signal from? The one out of the ECU is a square wave, whereas your dash is going to be expecting a voltage spike. If you're getting something at all, I'd say you have it connected to one of the igniter wires, there is two lots of them, one works up to around 4000rpm and the other after that, very weird.

What you need to do is hook it up to the proper tacho signal from the ECU, my ones from memory have been a black wire with brown bands. You'll need a tacho booster then, I made mine out of an old relay.

[turmite]

Spot on with your guess, igniter is were its connected and yes up 2 4000 fine and yes definatly weird! Whats the relay actually do?

[JustCallMeOrlando]

Converts the square wave out of the ECU into a voltage spike. If you have a search around the forums, you should find a diagram.

[turmite]

Thanx Dude, heaps have a good 1

[willwal98]

Just had a look at my ECU at lunch and couldn't find a black with brown bands anywhere but I was in a hurry and didn't have a torch. Don't spose you could narrow it down to a plug and a pin number or point it out on the 1ggte wiring diagrams?

[JustCallMeOrlando]

Gen2 or Gen3? Best spot to pick it on is on the plugs that are supposed to go to the chassis loom.

[willwal98]

it's a gen3 in my RA28.

[infotechplus]

Locate the G1 plug. It's pin 2, the black wire, comes from the Igniter and goes to Tacho.



Cheers,

Peter

[willwal98]

don't spose you feel like tracing that back to the ECU? Some of my plugs aren't the best.

[infotechplus]

don't spose you feel like tracing that back to the ECU? Some of my plugs aren't the best.

It doesn't go back to the ECU, not directly anyway.

Try Pin 1 on the "S" ECU plug (26 pin)

Sideshow suggested the IG- pin on Check Connector "N" in the engine bay.

Note: Your tacho may not work without a booster.

Cheers,

Peter

[willwal98]

yeah i've tried that before, it's been cut about 50cm's from the plug. Any idea where it is supposed to go?

[infotechplus]

yeah i've tried that before, it's been cut about 50cm's from the plug. Any idea where it is supposed to go?

More information required.

What's been cut?

Cheers,

Peter

[willwal98]

oh sorry, traced the IG wire from the diag plug and it ends at the firewall. I've got a multimeter (cheap and nasty) and a probe light. I usually use the probe light to find the tacho signal because the light pulses with the revs and it's quite easy to spot where the multimeter is a bit slow to respond. I have also looked at the pin you suggested on the ECU and get nothing from it (in voltage mode).

[willwal98]

I have traced that black IG wire back to the igniter (and it was connected to it) and connected it to my tacho through a home made booster (modified relay) and it works. Yet to take it for a drive to confirm it goes all the way around instead of stopping at 400rpm but i'm hopeful. + rep for all