To avoid fishing a wire thru the firewall, I'd like to tap the ECU for the tach signal.

My Questions are:
The "IG-" is a positive four pulses per rev, correct?
So I can tap either "NE" or "IGt" at the ECU?

For the record it is a 1994 Truck with 22-re, manufactured in california on 10/1993. And it wasn't plug and play for the cool toys, No tach, no Lights in the Coin/Ashtray.

Yes I've searched (closest answer is/was pin A25 at the ECU, and that doesn't work for my model/year).

Atleast it had factory radio plugs after I fished them out of the dash, and threads for the maplight with nighttime switch mirror.

*Edited* Clarify engine type

 

What's the engine?:

22R
22R-E
or
3VZE

I know you're not asking for an opinion, but, the only comment I'll make is, I'd stay away from the ECU. It is not too difficult to run a wire through an already existing firewall hole to tap into the coil.

 

Oops, it was there the first time i typed that out and timed out sorry. added it and clarified here..

It's the 22-re. It does not have the handy test port located at the coil pack either.

The EFI system is described at http://www.autoshop101.com/forms/h23.pdf it's a reprint of some toyota documents..

I have the wire set from a junker, I just sort of forgot where they came out of exactly. It's also 50 mile trip to go find out. The "IG-" at the diag port is the obvious choice, but man thats a lot of cable squeezed thru a little hole under the blower. I worry of chafeing and peer ridicule if I just fish it thru and tie it up to the bundle.

I don't mind given an/the opinion. So here is a direct question of them.

Would you tap a sensor or a trigger? (Yes it seems obvious) What are the ramifications of each?

 

Well it's cold out and I need the dash buttoned back up so I tryed it anyway, the answer is no (or I didn't push hard enough).

Tach wire is pulled thru the hood release grommet and zip tied across the firewall to the test port.

 

Gottcha.

Mine's a 22R and has the unused plug, so I used it.

I won't be able to help you with your 22R-E.