On my 1980 280zx there is what looks like a sensor under the throttle body with one white & black wire going to it, anybody know what it is?

My second 280 has the same sensor but a third 280 injection setup I've got doesn't.

Steve

Got pictures?

I'll try

My Chilton manual has a very vague wiring diagram, mentions an optional 'altitude switch' going to the ECU. ??

I've traced this white & blk wire to the back of the dash fascia, still not sure what it does. :sleepy:

The altitude switch, at least on my 78, is located under the dash. However, my car is a US 280Z. I don't know how that would differ from yours. Can you post a picture?

sensor pic

Sensor.bmp

You can see it below the throttle body and TPS with one wire going out.

That's the solenoid valve for the BCCD (Boost controlled deceleration device) which reduces emissions while the car is coasting. It does this by supplying extra air into the intake manifold to maintain the manifold vaccum at its correct operating pressure. It is present on my 78 280Z but not on my 79 810.

Thanks Stephen, Ive just fitted a 280 efi into my 240 and this is the last wire I need sorted.

Do you know what actives that white & blk wire on the solenoid? being pollution it should fire up even if I don't connect it.

Funny thing is, I can find it on the car but I cant find it in the wiring diagram. But it should work without it hooked up.

Okay, I did locate it in the wiring diagram as the 'B.C.C.D. Cut Solenoid.' The w/b wire t's into the check connector and runs to connector 1 (C-1) and continues from that connector to the one on the back of the speedometer. How it really works, I don't know. But it seems that it cuts out the BCCD as long as you're maintaing a steady speed or accelerating but lets it work if you are decelerating. Hope that helps you.