Idle switch function, can it be emulated?

[86BRATMAN]

ok, so I'm just trying to get all my stuff straight here for a project. Going be running an ej22e/25d turbo'd with an ej22t ecu swap. Most of it is pretty straight forward imo, but I have one thing that's nagging at me.

I have a really pretty ej20h intake manifold and throttle body I want to run with this particular build. The 20h throttle body is a 3 wire, from what I can find the voltage and such are the same. Except for the idle switch. Is there any way to emulate the idle switch without using a 22t throttle body?

[PhyrraM]

Google for nitrous oxide (NOS) throttle switches. That should give you ideas on how to mount an external idle switch.

Depending on the static resistance through the TPS, the 20H TPS might pull too much or too little current through the circuit, but I would think that's unlikely.

If your an electronics type, you could also build a circuit that reads the EJ20h TPS then converts them and simulates the proper signals to the EJ20G/EJ22T ECU.

[Legacy777]

What PhyrraM suggested about an external switch is a good start for ideas on how others have done NOS switches.

I think the static resistance should be the same between the 3-pin & 4-pin TPS's. Will the 4-pin TPS physically mount to the EJ20h throttle body or could something be fabricated to make it fit?

[86BRATMAN]

Changing the tps over was the first thing I looked at, but the 20h throttle body has a hook style connection to the tps like the obd2 subarus do. Only other throttle body I have available with the same "D" style shaft as the first gens is an ej18. I was messing around with it tonight and I believe I can fab up an adapter plate to properly orient the tps and kill 2 birds with one stone (iacv location on the manifold interferes with the bov on my wrx intercooler as well).

[Legacy777]

Cool! Yeah if you can do that, I think that'll probably be your best option.