What sensors are these? (lower drivers side)

About a week ago I noticed some wires were touching the side of the engine. Looked more and found the wires were run next to the exhaust manifold, a bad place. The split loom was melted and there is some bare wire.
(update: 89 XJ)

These wires go to the O2, 2 other sensors. The leave the wire bundle by the fuel pressure regulator. They are now routed down past the power steering pump. Which sensors, besides the O2, are connected to thes wires?
Searches have not produced any info on these.

The sensors:
1) The 02 has a three wire connector.
2) Sensor has a square connector, 2 wires and is located midway front-back just above the oil pan.
3) The other sensor has the usual 2 wire connector, it is located behind the motor mount.
I think one is the knock sensor. Can someone help identify these for me.

Do you expect people to guess the year? On my '89, the 02, knock sensor and CPS wiring run in that area. Knock sensor is the least critical of the three.

My apologies. It is an 89.
Isn't the CPS wiring at the back of the motor?
Do you know which is the knock sensor?

the knock sensor looks like an O2 sensor with square fuel injector plug on it... thats the best way to describe it .. the wiring for the O2 sensor and the Knock sensor come down from the front of the fuel rail and loop down below

On RENIX engines, the knock sensor is the lower of the two, with the FI-looking plug. It's damn near screwed into the oil pan rail - it need contact with solid metal. Another giveaway is the foil shield inside the wiring - it's there to prevent "false signals" from crosstalk from adjacent wires. This shielding goes all the way up to the bulkhead connector.

The second sensor - forward and up a bit - is the coolant temperature sensor; the one that reports to the ECM. RENIX has a total of three - that one, the one in the cylinder head that reports to the gage/light in the panel, and the one in the radiator that turns the fan on and off.

The HEGO wiring you already have sorted, apparently.

The other important element on that side (although it is a huge pain to deal with) is the block drain plug - but it is usually easier to pull the CTS to drain the block, since the drain plug is (apparently) 8mm square drive...

5-90

Thanks 5-90.

I after a quick fix on those wires the XJ ran for several days then did not start. Diagnosing the starting problem, I found the check valve in the fuel pump was toast. But is still would not start. I pull the wires apart and seperate each wire to give it a good look. Not good. IT was worse that I had thought. The knock sensor wires set has 3 wires. One bare wire that runs to the end of the foil wrapping. That wire must have become hot enough to start melting the insulation on the other two I could see the wire through a thin film. One wire to the coolent temp sensor has lost most of the insulation for about 2 inches. I had seen the before and covered it.

To patch this I coated any expsed wire ith liquid e-tape and let it cure. I then wrapped each coated area on athe wires with e-tape. Wrapped the bundle of wires with e-tape and new split loom. This cured my starting problems.

Now as the foil wrap is not missing from aboutn 4 inches of the knock sensor wires it that going to be a problem?
If it is a problem can I replace the foil with another shielding material?

DaveW said:

Thanks 5-90.

I after a quick fix on those wires the XJ ran for several days then did not start. Diagnosing the starting problem, I found the check valve in the fuel pump was toast. But is still would not start. I pull the wires apart and seperate each wire to give it a good look. Not good. IT was worse that I had thought. The knock sensor wires set has 3 wires. One bare wire that runs to the end of the foil wrapping. That wire must have become hot enough to start melting the insulation on the other two I could see the wire through a thin film. One wire to the coolent temp sensor has lost most of the insulation for about 2 inches. I had seen the before and covered it.

To patch this I coated any expsed wire ith liquid e-tape and let it cure. I then wrapped each coated area on athe wires with e-tape. Wrapped the bundle of wires with e-tape and new split loom. This cured my starting problems.

Now as the foil wrap is not missing from aboutn 4 inches of the knock sensor wires it that going to be a problem?
If it is a problem can I replace the foil with another shielding material?

Click to expand...

The knock sensor shield isn't too important but I don't even run a knock sensor anymore. Just don't lug the engine while driving/cruising and you'll never even know it's gone.

FYI - You can connect a small audio preampifier to the knock sensor and listen to it through headphones and/or your stereo. It's very much like an acoustic guitar piezo bridge pickup if you have any experience with something like that.

If the shielding is not that important I will let it go for now.
If I notice any performance problems under load or lugging I will have to look into it more.

Thanks