I need to know which one is the coolant temp sensor that the ECU uses on an MY98 WRX.



Cheers,

Wayne.

 

the two pin brown one on the right

 

2 pins as in 1 for the ECU and the other for the gauge?

 

Does it not have 3 pins? Pin 1 5v from ECU, pin 2 return to ECU and pin 3 to the temperature gauge.
Kevin

 

the one to the right is water temp sensor, the one on the left is for the water temp gauge inside the car

 

brown one on the right as has been said..

the other signal spade connector is the sensor for the dash gauge

Simon

 

I stand corrected
Kevin

 

Cheers for the info guys. I am replacing mine soon and just wanted to know which one it is.

FAO Simon,

Ok, carrying on from this, I was going to use a resistor to fool the ECU into thinking that it was running a coolant temp of 60-70c but have since remembered that I can change the water temp correction via datalogit. If I use the resistor I can switch it in and out, but if I alter the PFC settings I can't unless the laptop is connected.

What would be the effect of having a value of 1 in ALL of the boxes above 10c? Would the car still run or would it stall (using petrol).

The reason I ask is this. I can start the car on LPG and as long as I don't go daft the vaporiser doesn't freeze and the runs ok, although using the PFC's enrichment its a little rich. It doesn't need the enrichment on gas and is simply using more gas than is needed. So it's an economy thing really.

Any thoughts?

Wayne.

 

just to clarify.. on cold start you don't want any enrichment?

 

I knew you would say that!!

When its starting on LPG I dont want any as it doesn't need it.

Its only when I start on petrol that it needs it and I want to avoid starting on petrol if I can help it.

 

so the pfc is controlling the lpg?

 

Yes, exactly that. The gas ecu simply mirrors the injection signals from the PFC and adapts the signal to provide the equivalent gas injection times. So by shutting off the water temp correction the gas ecu follows suit.

Many of the LPG users I have spoken to do the resistor trick to save some petrol on cold starts. It also has the added benifit of reducing the wear associated with petrol enrichment.

Wayne.

 

cool... you have the advantage of seeing the temp on the commander or datalogit etc..

Simon

 

I think I may test the water temp correction method in the morning to see how it affects the petrol running.

 

you can probably get away with leaner on cold start except the idle.. the idle is usually the pain..

if you are intending running lpg 99% of the time.. you could just add a couple of % to the injectors until warmed up if you had to use petrol on a cold start when out of lpg?

Simon

 

Good thinking simon! I have the commander on the dash so could do exactly as you say.

Cheers,

Wayne.

 

if you run wideband then you can test it