Auxiliary Fan Question and running rich

[92zXNY]

Sorry, i've spent days searching on google and on here..no luck.

My car has been running rich (100mpg on half tank).TT swap into a 2+2. All new injectors etc.

I know the idle air controller is working because i tested it with the 12 volt and also took it apart and sprayed it with cleaner

I replaced the CTS sensor from Z1 ( also cleaned the connections)

I noticed when i first start the car the auxiliary fan kicks in..this never happened before with the old sensor nor when the car was a N/A. Is this normal? After its warmed up or driven for a few mins the fan turns off. ( NO, the A/C isn't on.)

Just wanting to make sure this is normal or if z1 sold me a defected sensor.

Thanks very much

[DTRUONG9]

I have the opposite problem, my fan doesnt work. when you did the swap did you use the fan from a tt or the n/a because they are different and run at different temps.

This link might help
http://www.twinturbo.net/nissan/300zx/t ... uxfan.html

[92zXNY]

I have the opposite problem, my fan doesnt work. when you did the swap did you use the fan from a tt or the n/a because they are different and run at different temps.

This link might help
http://www.twinturbo.net/nissan/300zx/t ... uxfan.html

i read that article. everything works as suggested in it. I'm using the N/A fan because i kept the N/A harness and use Z1 TT to NA ECU conversion.

So i'm guessing the fan isnt suppose to kick in on a cold start? Also i wrapped the sensor with plumbers tape when i screwed it in..could that break the ground and cause this issue?

[92zXNY]

Anyone please? All you have to do is start your car and listen for the fan to kick in and time when it turns off. Just make to sure sure if my cts sensor is working

[skywhine]

Also i wrapped the sensor with plumbers tape when i screwed it in..could that break the ground and cause this issue?

Absolutly. Temp sensors are tappered thread, so the more you tighten the sensor, the threads actually "crush" together creating a seal..And a ground. Its possible the thread tape is affecting the circuit. All temp sensors are simply resisrors. When cold they provide a certain resistance, when hot, a higher/lower resistance. The ecu see's these resistances and outputs a signal to whatever the temp sensor (or resistor if you will) conrtols.

Now im a Toyota trained Tecnician by trade, however i prefer nissanss . On toyota their is generally 3 temp sensors. 1 conrols the gauge in the dash, one contols the fans (when applicable mainly transverse mounted engines) and one transmits a signal to the ecu which controls fuel injector duty/AFR to an extent. And if you go back far enough (obd1) their is a 4th sensor for the cold start injector, but thats irrelevant cause Nisssan didnt use cold start injectors, rarther more fuel in closed loop (Cold start).

So exactly which sesor did you use thread tape on: the single wire or the 2 wire?

Its also possible the sensor itself is faulty. Did you use the NA sensors or the Turbo sensors. So as far as the MPG goes, a faulty temp sensor CAN cause the ecu to never realize the engine is warmed up and stay in closed loop, which intern dumps alot extra fuel in. All you need to test the sensor is DVOM (multimeter). Look up spec for resistance when cold and hot, then test. If its not within spec replace.

[92zXNY]

I'm actually referring to the Coolant temperature sensor that sends voltage to the ECU rather than the cluster.

I didnt know the NA and TT CTS sensors are different?? please confirm this, because on Z1's website they didnt specify the differences. Also from other write ups, its noted that both TT and NA sensors are interchangeable.

The sensor seems to be within specs.

My real and main question is, does your auxiliary fan turn on for 20-30 secs after a cold start? Anyone, please remember to listen for this and let me know asap. I'm still trying to figure out whats causing my rich conditions. Im 120 miles per tank

Thanks very much.

[Ace2cool]

The sensors aren't different to my knowledge, but the specs for when it should turn on and what speed are for sure.

http://www.twinturbo.net/nissan/300zx/t ... uxfan.html

Read that, and there's no reason for anyone to start their car and listen. Doesn't matter, as ambient temperature while it was sitting can play a big factor in if it were to turn on/off. Also, this thread should've been created in tech. I'm gonna move it there.