Coolant temp sensor nightmare, please help me solve this

[corey240]

Ok, so iv searched and searched a couple forums and did a couple test to my understanding and helped nothing.the car is a 98' s14 with a redtop sr, front mount, exhaust, walbro fuel pump. heres the problem, the car sat for roughly 8 months with nothing ever messing with the ecu or the wiring to it. i rebuilt my motor, now i put it in and long story short i checked for codes and its 100% the coolant temp sensor , whether its wiring, or a bad ecu, i dont know. but it has all the symptoms of a bad cts, the temp gauge doesnt work, and the ecu is throwing code 13 aka cts problem. so i swapped the sensors with 2 others of each kind and the same thing, i swapped the sensors and reset the ecu with no avail.

I have followed the wiring to the sensor for the ecu and all is good. the wireing for the gauge sensor is also good up to the ecu area where i didnt see the need to follow into the dash because...

Prior to the rebuild back when the motor blew, it ran fine until the rod knock. the gauge worked, i had code 55 (nothing wrong) and all was great (except for the rod knock). so now i am totaly confused on what can be wrong, how could my ecu be bad? is it bad? (i h ave no other sr's to swap ecu's with to test), could the wiring for the ecu sensor have just gone bad and needs replaced? (meaning the wire thats wraped with a ground wire needing replace),.

what should i do to figure this out? i cant find what to turn my multi meter to, to test the wires coming from the sensors, i know what they should be at but i dont know what to set the multi-meter to. im trying to come up with a list of considerations to test and replace. when it comes down to it i think either for some reason the ecu went bad or the wire just went bad somhow and doesnt wnt towork anymore.