Yea, I know, would be better with a pic but we didn't get one but hopefully this will be easy biased on the location and type of connector.

Yesterday while working on my '96 4.0L and using a mirror and light to see under the intake manifold following along the secondary air-injection pipe seeing what was needed to remove it I noticed a sensor on the side of my block that's connector from the wiring harness had been zip-tied in place by someone in the past (I'm only the 2nd owner and it wasn't me). I looked close at it and it appears the connector for the sensor is broken, the little metal wire you usually press to release the catch to unplug it missing (and no place to put it even if it were there). I didn't undo it to take a picture since it's running and zip-tied in place but I'd like to identify that sensor and see if I can find a replacement end for that wiring harness connector to fix it back properly.

It's the drivers (left) side and the sensor is just in front of the starter and about the same height, toward the top. In fact I can easily imagine someone breaking it while changing the starter at sometime in the past which probably explains how it it got broke.

It is one of the connectors similar to what plugs into the MAF where you have a rectangular connector with a little wire on it you squeeze when taking it on and off. There are a couple of more sensors on that side of the block but they are further forward, one just behind and one just in front of the oil filter which I assume are oil pressure sending units but those only have a single wire going to a blade connector. This one has at least 2 wires going into it, maybe 3 but I think 2.

This is the only sensor that goes into the block on that side close to the starter that has that type of connector that has the wire you press and is more or less rectangular shaped. So I'm hoping it's easy to identify.


Then the question is, does anyone have an old cut up harness with that connector that they'd sell me the connector with enough length of wire still on it that I can splice it in properly, or does anyone know where I can get a new replacement for that connector?

 

Offhand it sounds like one (of the two) knock sensors


Cheers
DD

 

Thanks, Just looked up a picture of one and that does look like the right shape/size for the plug I'm seeing (what I can see of it in the mirror). Looks like Standard even makes a replacement pig-tail with a new connector that has a 6" set of wires coming off of it for replacing damaged ones, Standard part #HP3980. Advance Auto Parts also carries one for $6.99 in stock though theirs is a different brand with a different part number.

 

Don't do away with the extra wire you see zip tied. From what I have read, this is normal, as the extra wire creates the correct resistance. I think mine were shortened, and the check engine light wont go out, showing both knock sensors at fault, yet don't feel they are.

 

It's not an extra wire, this isn't anything the factory did. What's apparently happened is someone has broken the connector (probably changing the starter) so they took a small yellow cheap'o zip tie (one of those real tiny ones) and went under the shoulders of the sensor, around the connector between the two wires, back around the other side base of the sensor, and then back through itself zipping it closed so the zip tie is holding the connector onto the sensor even though the connector is broken away most of the way around. The connector is all broken apart so without the zip tie someone has added it would just come loose going down the road.

 

All I know is that another thread had a description of original knock sensor wiring. And the original wiring apparently appears as though someone put too much wire. Not sure how it was/is secured, only thinking mine has been shortened, as PO states light came on after the octopus hose was changed by mechanic. I've looked into it, and it seems logical that someone would shorten the wire out of misunderstanding British engineering logic.

 

I just finished soldering on the new connector, marine grade heat-shrink, did everything the proper way. So that's fixed.

I was gonna let you know though that I think I seen the wire you was talking about, when I pulled the split loom back to do the work I found another white wire under there with a tuft of electrical tape on it and folded back on itself and taped back to itself and then to the other wires.

But the zip-tie was something the original owner or some mechanic had added just to hold the broken plug from falling off the sensor.

So all is good now.