Subaru tach

[Eatoniashoprat]

Hey, for those with their conversions completed and working...

Did you hook your tach up to the tach signal wire directly from the ecu?

The reason I ask is because this doesn't work on my EJ22 van and it doesn't work on a lot of distributorless ignitions since the output voltage of the ecu tach signal is so low, the tach doesn't pick it up properly. You can buy 'adaptors' for this that basically boost the ecu tach signal ($80). Another guy I know has it wired directly to his ecu and it works fine. I just thought I'd see what people on here experienced so I know kind of what to expect when mine gets running.

Mike

[ricola]

I had my tach modified in my speedster, but I have seen diagrams of simple circuits made up to take the signal direct form the coil pack whihc provides a bigger signal, think it was on the subaruvanagon yahoogroup..
Rich

[Eatoniashoprat]

Thanks Rich, It seems maybe that some tachs or subaru MY will work just by hooking it up to the ecu, but so far I've seen more that do need some modification.

I would imagine to make it work that you could just splice into two of the igniter wires going to the coil packs (1&3 or 2&4), and use a diode in each line so you're not shorting anything.


Mike

[ricola]

yes, that's how it works, but as there are only two coils within the 'coil packs' as they are wasted spark, you splice into the two...