Hey guys. Now I'm looking for the location of the water temp sending unit on a 1989 IROC-Z 350 TPI. Thanks again.

 

The CTS for the computer is in the front of the intake, a 2 wire sensor, one black one yellow.
The sender for the gage is in the drivers side head between #1 & #3 cyls' spark plugs. Single wire, I believe it's green.

 

Please clarify:
Coolant Temperature Gauge sending unit: between cyl 1 & 2 single green wire, spade lug type connector.

or,

Coolant Temperature sender (CTS) to ECM; front of intake below Throttle body two-wire connector yellow & black, same as IAT (intake air Temperature Sender rear of plenum under side.)

FYI
There's another sender to left of the CTS, this is the coolant Temperature Switch for the cold start injector for those who have the Nineth Injector. It has same connector as the Injectors.

 

While where talking about temp sensors. What is the temp sensor on the passenger side head by the #6 cly.? Single wire on the 305/350 TPI.

 

r u talking about teh circle shapped 1? if u are thats the knock sensor. tells the computer when it has to retard the timing.

 

I beleive the sender beside the CTS is the "Cooling Fan Switch", the CTS and ECM controls the "9th injector"...

The one you're looking for is a single "Green" wire, spade connector, sender on the drivers side head between #1 & #3 spark plugs...

 

Fan switch for the secondary fan.

 

nope, 9th inj. is only controled by the cold start switch, next to the CTS in the front of the intake

single green wire sensor between #1 and #3 cyl is guage sender

single green wire sensor between #6 and #8 is fan switch (for single fan car or for secondary fan on dual fan cars)

 

Mine doesn't have one, but I went back to the books, and you're right... I had forgotten...sorry raul.garcia...
My cold start circuit uses all injectors controlled by the ECM using the CTS reference...
The ESC(Knock sensor) is in the block near the starter...