Josh B

I'm trying to wire up a Zeitronix ZT-2 in my 968. I've got it installed with a wideband but would like to pull in a tach signal and the TPS switch signal. Does anyone know which wires on the harness on the DME I should tap into for that?

odurandina

the answer will come... until then, jumper lines to the coil.

Lear35A

The wiring diagram Sheet 6 shows the throttle valve potentiometer and the engine speed sensor going into the "control unit." It looks like the throttle position is a white with green stripe wire at connection 53. The engine speed sensor has two wires going to the control unit, one white at connection 49 and one brown at connection 48. Not sure which would give the right signal to the Zeitronix.

Josh B

Thanks! On a 944 turbo I've pulled a tach signal before from pin 21 on the DME labeled "4-pole separation point terminal 2 Tachometer" Green/black wire...

Lear35A

Pin 21 on a 968 DME says Malfunction Indicator Lamp. The engine coil is pin 1. Maybe that would give you the signal you need???

Cloud9...68

This is a really dumb question, but what will pulling the tach and TPS signal into your Zeitronix give you? I have and AES A/F ratio meter that connects to the wide band O2 sensor that came with the unit, but it never occurred to me to pull in additional signals. How would those be displayed? Thanks.

Josh B

With the Zietronix you can data log to a laptop easily. With those two data inputs I can look at A/F against RPM and TPS and then look at those vs a dyno run. Certainly overkill for a NA car but fun all the same. There is one more signal I can data log so I could put in a fuel pressure sensor or look at the voltage coming from the MAF.

For future reference I used pin 6 on the DME connector for the RPM signal which also connects at pin 2 on the small rectangular block under the glove box.

badcoupe

Log the maf voltage that way if you ever decide to add a piggyback it'll be easier know where to "massage" the signal at

Josh B

I thought about that. Looks like Pin 7 is labeled "Signal" from the Air Flow Sensor. I've got an SMT6 I could wire in

Any ideas on the what the optimal A/F is under load on an NA car?

Cloud9...68

Thanks for the explanation - makes sense.

badcoupe

Mid 12's isn't too bad some like it in the lower 12's only problem is not being able to adjust timing you may have to have to stay a little fat on fuel.