[Rusty]

On my 1975 280z there is a sensor coming off the side of the thermostat housing that has two wires coming from it. They are broken at the base with no good way to fix them. However I'm not sure what sensor this is. There are two other sensors at the front that I presume are temperature sensors for the computer and the gauge. But I'm not sure......

Thanks for the help all,

Rusty

 

[ConorP]

Although the placement of the sensors varied a bit year to year, here is a reference to a '76.

http://www.zcar.com/forums/read.php?f=1&i=219549&t=219492

Is the car running? I'm guessing very rich.

ConorP

 

[yo2001]

That's for automatic car. something to do with vacumn solonoid. You should have four sensor then. two injector connector looking sensors, one wire sensor, and the two wire sencor that you are talking about.

 

[gene_w]

Not necessarily. I think the 240 and 260's only had them on the autos, but the '75 280 had them on all of them, I'm pretty sure. Mine has it as well, and one of the wires is broken off as well. I have run over the wiring diagram several times and figured out what is going on. This sensor is used to control the timing when the engine is cold. The distributor has two coils, one normal, and one advanced. The senser you spoke of determines which of these coils is used. When the engine is cold, it advances the timing to burn the cold, rich air/fuel mixture more completely. I'm pretty sure that the wires being broken disables this advancing, so you should be fine. Just set your timing where it needs to be, and don't worry about it.

If you do happen to find a source for this sensor, let me know, as I would love to get one to replace my broken one.

Gene

 

[Rusty]

You've got that right. Started running very smooth when cold then progressively got worse. The plugs are 1 day old and they are black from running toooo rich.

The car now misses but didn't initially until it warmed up. I suspect that I need to clean the plugs.

Rusty

 

[liquidcmr]

This is a copy of an older post of mine.

I would check out the water temperature sensor. Does your car run "normal" when it is cold and then starts to run rich as it warms up ? If the answer is yes, I would say you water temperature sensor is busted or has bad connections. One easy way to test if this is the problem is to let the car warm up and then disconnect the sensor. When you disconnect the sensor in a good working car you will hear a difference in the idle and the car will run rich (this is because the computer thinks your car is cold and therefore lets more gas through the injectors). The water temperature sensor is the one above and to the right of the Thermotime switch you can disconnect it at the sensor or at the bullet connections about 12 inches from the sensor. I would go with the bullet connections.

Good luck
- Chuck


P.S. Rusty, it sounds like your sensor is already disconnected.

 

[john cross]

You need to fix that. You engine will run totally different. This is the most important sensor input to the computer.