NotSure

All,
I am having issues with my 22re and would appreciate any help you could offer.
Thanks!!

Vehicle Details:
-1986 4runner 4wd 5spd Manual
-Refurbished 22re with 180 miles on it (still breaking in)
-New almost everything
-EGR deleted

Problem Description:
-I have a 28 mile commute, mostly on the freeway.
-Drive in: everything runs nominal.
-8 hours later: on the drive home, 10-12min in I start to see an intermittent CEL and an occasional stumble. After I am off the freeway (20min of driving) I have to really goose the throttle when taking off otherwise the engine will die under load. CEL is now always on.
-When I get home the engine smells like it is running rich and I get a code 4 (water temp sensor bad or circuit open).

Steps taken:
-The temp sensor is a new OEM sensor and I have done an ohm test with hot water and ice to confirm its operational.
-Recently had the intake manifold off, check voltage and resistance on the THW and E2 wires while moving the harness to test for a short. Nothing.
-Double check timing.
-New thermostat
-New battery with new wires and terminal
-replaced grounding wire (head to firewall)

Side notes:
-I am seeing a pulsing in the idle when I push on the brakes. I do not think this is related but include it just in case.
-Coolant levels look good. I am running the Toyota red coolant.
-when idling no CEL. CEL kicks on at about 2k rpm
-seeing a pulsing at 1.2k rpm.

Question:
Are there any other temp sensors that can cause a code 4? In reading the FSM I think its only the green plug sensor on the front of the intake. I do also have a secondary temp sensor on the thermostat housing. No clue what its for or if it can cause a code 4.
Is it possible an incomplete coolant burp could cause this??

JoeS

On my 86 the two sensors are for water temp. One for the ECM (green) and the other Cold Start Injector (black). They are located side by side just below the coolant thermostat on the front of the block.

NotSure

on my 86’ i have 4 temp sensors. The green plug on the front of the intake manifold (sends signals to the ecu. my suspected problem child) the brown plug (cold start timer) a sensor on top of the T-stat housing (not sure what this guy is doing) and a little guy on top of the lower intake manifold in between cylinders 2 and 3 (sends temp signals to the cluster)

As I understand the fsm, only the green plug sensor can cause the code 4 but I’ve read conflicting information on the internet.

coryc85

The temp sensor ground path is through the threads to the intake, through a ground wire connecting intake to body ground. I assume you tested the sensor removed from the truck, next time it acts up on your way home, as soon as you shut down the truck, pull the connector and check the resistance from sensor to battery ground and see if you get a bad reading. If so, then clean the threads inside the hole really well, clean the threads on the sensor, and check that intake to body ground wire, the wire itself and it's connection points need to be clean and shiny.