hackengineering

Hello i just purchased an 87 4runner with 22re. It has a ton of small issues but runs great and should be great start to my next crawler. I have been trying to research and learn a bit befor i posted but i have run into an issue with the temp sensor and temp switch. I have not been getting anything from the temp gauge in the instrument panel and i also noticed last night there are actually two sensors located in coolant. One right after the thermostat the other a bit lower between the 2nd and 3rd cylinder. The second one does not have anything conected to it at the moment. The other thing is i have a two wire conector that is T shaped that is not attached to anything. Both of my temps sensors are single wire.
Am i to assume one of those should be a two wire sensor and which one actually runs the gauge.
Thanks in advance for the help.

myyota

Both temperature sending units have a single wire plug. The temperature sending unit located between the 2nd and 3rd cylinder is for the temperature gauge, the temperature sending unit on the thermostat is for the a/c. The green wire with the blue wire spliced to it is for one of the temperature sending units. The two wire plug looks like it might be for a vacuum switching valve that your missing. I also see a vacuum port on the back of the upper intake that has two capped off hoses on it, the vacuum hose from the fuel presure regulator should be hooked up to one of them.

hackengineering

Thanks for the reply, That is great info about the two temp sensors. Thanks to your comment i was able to find the missing single wire and now my temp guage works.
I am planning to start going thru the vacuum lines tonight. There seems to be alot for the A/C which i have no use for. I have PDF of the service manual for an 88 4runner so i am hoping that will work for the vacuum diagrams. I am assumeing the vacuum switching valve you mentioned is also for the A/C.

myyota

There are actually two vacuum switching valves (VSV), one is for the a/c, and the other vsv is for the fuel presure regulator, but its not needed. I removed the vsv for the fuel presure regulator on my 4Runner and ran the vacuum line right to the vacuum port on the manifold.

4runnerx3

This is the only pic I've ever found in the FSM that mentions a temp sensor on the t stat.