axledeep

This one has been driving me crazy. As many of you know, there is a bank of sensors between the intake plenum and firewall on the 3.0. I am trying to ID a few of the sensors, as my setup does not look exactly like all the pics I've seen nor the FSM. I know these sensors are arranged differently depending on year and possibly also depending on auto vs. manual tranny. Mine is a 1990, 3.0, 5spd.

I've attached a pic. Starting from the sensor on right (green plug) - can anyone positively ID these sensors for me.

GREEN on right = Engine Coolant Temp. Sensor for ECU?
BLACK to the left of green = ? (depending on what I read, it is either the Cold Start Switch or some mysterious "Water Temp. Sensor")
YELLOW = temp sender for gauge cluster?

Is this right?

Thanks!

JonnyBoy

From left to right:
SWITCH, WATER TEMPERATURE (FOR E.F.I) Toy part no 89428‑14070
SWITCH, START INJECTOR TIME Toy part no 89462‑20040
SENSOR, WATER TEMPERATURE (FOR E.F.I.) Toy part no 89422‑20010

axledeep

Thanks so much! Two more questions...

The YELLOW Switch on far left, 89428‑14070. Is this what sends signal to the dash gauge, typically referred to as the Temp. Sender? Does it have any other purpose (ie does it send any signal to ECU or can it actually affect how the motor operates)?

The GREEN Sensor on far right, 89422‑20010. Is this what tells the ECU what the coolant temperature is at?

I'm trying to narrow down a coolant temperature based idle issue. Thanks for your help!

JonnyBoy

I'm pretty sure the yellow and black ones, since they're switches, not sensors, control the efi, and the green is the gauge sensor.
I could be wrong, but the terminology used leads me to believe I'm right.

axledeep

Hmmm, well...I'll keep digging then. Do you have an FSM for the 90 that has these sensors located the same as in my pic? I have an FSM that I thought was for my 90, but the sensors are laid out differently than what is in the book.

JonnyBoy

http://www.toyodiy.com/parts/p_U_199...MGEA_8404.html
There's where I referenced it.