So I would like to use a GM IAT sensor but have a couple of questions about that:

I noticed that there's an open element and a closed element version. What is best?
Also where about would be the best place to place it in on my ITB? (In the intake manifold? On the air Filter?)

Also About the coolant temperature, can I not use the stock on? Of would I nee to get a GM one too? If using the stock one, would just splicing into the original connection to make a T connection work or would it give out an incorrect reading since its feeding 2 things instead of one.

Sam

 

Splicing a coolant temp sensor will give you an incorrect reading. The thing measuring the sensor has a resistor inside its circuit, and it is measuring the voltage across this known resistance value, and this allows the measuring circuit to infer the resistance of the sensor, which in turn gives you the temperature. Assuming you know the temperature vs. resistance curve of the sensor.

They would most likely do it in only one step, however

You put an open IAT sensor right infront of the throttle body, and you put a closed element sensor inside the coolant under the thermostat.

Personally I would use both the stock sensors.

What engine are you looking at megasquirting?

Assuming its your 84GS

I'm planning on using one of these on my 82GSL

 

Open element for air temp, anywhere in the intake air stream for an n/a should work. If mounting to the intake you may get heat-soak problems when hot-starting. Farther back towards the filter would be better.

The efi'd rotaries have a coolant temp sensor that is located on the backside of the water pump. That's the one to use. No splicing required in a 1st gen, as the dash gauge is driven from the sensor down below the oil filter. Forget about the T connection. Mixing signals is a mess unless you research it well and know exactly what you are doing.

 

Mines an 84 GSL too. Thanks Renns i totally forgot about the sensor in the water pump. Its also on non EFI cars like mine. It controls the electronics choke return from looking at the diagrams.

So open element it is for the IAT then. Out of curiousity does open element refer to that its basically open to air and closed element means its withing a closed system like the intercooling piping of a turbo or supercharger?

 

K so I won't be able to use the IAT on the air cleaner box, so inside the Manifold it would be. Now does it result in a slightly colder air sensing as the fuel would probably cool the air charge a bit right?

 

You can't use the temperature switch in the back of a non-efi rotary waterpump. It is just a switch, that changes state past a certain coolant temp. It is not a sensor at all. I thought about doing this myself, but after reading the workshop manual and posting a question on another rotary forum I visit i realised this is not possible

 

Do you know if the sensor from the FI car is a direct bolt on to it? If so I can just pick one up from one of the yards and stick it in there .

 

nope they don't make it easy. What I did on my RHD vehicle, is get a 86-88 Turbo model waterpump and then block off the 2 water tubes.

Theres quite a few things you need to do to get this to bolt onto the motor though. These things include

removing metal from the 12A Alternator bracket
enlarging the hole in the front of the waterpump
tapping a hole in the waterpump for the alternator bracket to bolt to
blocking off the turbo water return (its near the lower hose)
blocking off the BAC valve water return (its near the mazda coolant temp sensor)

 

well, if you get a water pump off of an NA, you at least dont need to block off the turbo water return. Everything else you'll need to do. Could you drill out and re-tap the existing hole for the 2nd gen temp sensor? It seems like that would be easier, and as long as you used some teflon tape when installing the sensor or something it should be fine

 

http://www.steigerperformance.com/PRODUCTS/sp40001.html

Wouldn't going with something like that and using the Gm closed loop sensor just be the easier way?