Hi guys, I' m wondering what is that sensor, near the temp one. It can't be the gauge sensor, since on the 3.1 V& LH0 (mine engine) it' s on the drivers' side.

Someone can help me to figure out this?

 

Possibly a temp sensor for the ECU, however the guys who frequent the V6 board will be able to tell you for sure.

 

The connection on the end says fan switch to me.

 

That is some sort of aftermarket sensor, as in my car there is a bung plugging that hole.

 

It is the cold start switch that is used on the prior 2.8l engines. Likely the lower intake is left over stock from '89 and used in the '90 MY vehicle.

RBob.

 

cold start sensor/switch is also 2 prong not single connection

not possible to use the lower from a 2.8 on the 3.1 due to the vacum passages in the lower intake , 2.8 feeds aic air into air passages in the lower intake to carry fuel from the cold start injector directly into each port
the pcv valve si also plumbed into theese passages

the 3.1 intake has no air/vacum passages in the lower intake because it does not use a cold start injector and the iac directly sends air behind the throttle body

so the factory would not use the 2.8 lower on a 3.1 , however they do interchange with a few vacum line changes

 

Interesting information about the 2.8l lower intake. So in this case it appears that a fan switch (or similar) was used to plug the hole where the cold start switch resided in the 2.8l engines.

RBob.

 

That is what I am thinking as well.