1994 S-15 Jimmy with 4.3L CMPI, Vin W, 4x4, automatic




This is a connector coming off of the passenger side engine wiring harness. It's an oval 2 pin waterproof connector with only one green wire going to it.



This is where i think this melted connector attaches to between exhaust ports 2 & 4. I believe the plastic housing it plugs into is actually missing. Just the metal part of the sensor left.



This is the knock sensor I believe between exhaust ports 3 & 5, and the terminal on this sensor is loose and could be part of my problem.

I'd like to identify these parts and repair the sensor issues before i start buying fuel pumps and fuel injection units lol.

If I can figure out what this stuff is I should be better able to identify the problem

ACDELCO Part # 21377 {#25037332}
SENSOR,ENG Coolant Temperature Gauge w/4-SPD AUTO TRANS(M30) or 5-SPD M/TRANS(MY2); 2 BLADE TERM-CAN BE USED AS 1 TERM CONN-3/8-18 THD

It can be used as a 1 terminal plug it says. Looks very similar to what is in the truck. From my knowledge in EFI, I believe some systems utilize a 2 coolant temp sensors or sometimes a coolant temp switch and a coolant temp sensor, 1 for the PCM/ECU/VCM and 1 for the gauge in the gauge cluster. hmmmmm I will hit the books on this one

ACDELCO Part # PT728 {#12126458} 1-WAY FEMALE BLUE
CONNECTOR,SW-ENG COOL TEMP IND w/4-SPD AUTO TRANS(M30) or 5-SPD M/TRANS(MY2) or HVY DUTY HTR(C42) or A/C MAN CONT(C60)

This looks exactly like the connector that is melted in my picture. And it matches the shape of the connector on the sensor i posted earlier

 

"This is a connector coming off of the passenger side engine wiring harness. It's an oval 2 pin waterproof connector with only one green wire going to it."


I wanna say that is the engine coolant temperature sensor where that should be connected on the passanger side cylinder head.

 

That looks to me like the wiring for, and the coolant temp sensor for your gauges. It would appear that the top of the sensor is broken off, and the plug is melted.

Those 2 parts you have chosen should do the trick, and your temp gauge will work properly again. Might want to tie the wires up well so it wont happen again.