Ok, so I’ve got this nagging question

I have a switch on the dash (check photos) that is nowhere in either the service manual or owners manual. What the switch does is act as a choke. When the switch is set to the dot, the car runs fine (if not a little rich), switch it over and the car fumbles and tries to die, even while driving. According to my Owners Manual, this switch SHOULD be a headlight washer switch; something I don’t have. If this is for the choke, which I believe it to be, how would I adjust it? I’ve fiddled with the Idle RPM, but the car will not idle high enough with the switch in the off position. Very odd. The item in question here is #9, located bottom left under steering wheel, on the column.

Looks like an aftermarket switch someone has added. You'll need to trace the wires to see where it goes, but my guess is that someone has tried to add a manual switch for the cold-start injector. Exactly how they've wired it is anyone's guess.

Lovely. Thanks, Arne-will do in daylight

This makes me wonder-if you are right Arne, and I think you are, then am I basically driving the only 7 cylinder z around?

this might explain some of the poor gas mileage and the occassionally strong smell of gas-occassional because it's only noticable while going downhill (don't know why)

I figured the fume smell was due to vacuum hoses, so I switched most all of them today. Slowly but surely this car will be done

You could just take off the connector on the cold-start injector and see how the engine will go. But I'm puzzled as to why they would put a winshield washer fluid button separate from the wiper controls, in a place where you can't get to it easy (like the hazard switch.)

Plus, your 79 shouldn't need a switch for the cold-start injector; the engine ECU should have that. (actually the thermotime sensor does).

He said HEADLIGHT washer not windshield washer. ZX's don't have thermotime switches as that function is in the ECU. If you've ever seen a 79 and up ECU it has that warning on it that it not be used in a 78 or earlier car due to the possible damage it can cause to the system and the ECU itself.