1996 (corrected) 850 NA hot stalling

[850oldschool]

Done!

Thank you!

Junkyard for the harness and/or connectors - very, very cheap and you have several to choose from in Minneapolis.

It's about a 50 mile round trip to the u-pull, but they do currently have a few P80's. I'd need to make it worth my while. The shell of the connector in the picture is actually in pretty good shape for having been baked right by the engine for over 20 years. There's a fair amount of buried corrosion when you look down into the terminals with a bright light. I'll try some experiments to see if it can be cleaned up. I think a lot of frustrating unreliability is caused by bad sensor connections.

[erikv11]

At least it's just a knock sensor here - the only effect corrosion would have is a knock sensor code, rather than any actual engine function. In this case of course. I agree, dirty connectors are giving more and more issues these days, they are showing up a fair bit on the forums.

People really like DeoxIT for cleaning connectors. I've used it a few times seems to be helpful.

[850oldschool]

Okay, I got the wiring harness (9442158) and it has 2 male plugs on it, just like the plugs on the knock sensors. WTF? It's number 31 on the parts diagram, and right next to it is number 30, which is described as "knock sensor".

It says "made in Finland" on it though, which is pretty cool.

A little more digging, however has turned up a 2 pin connector identical to the one I removed with the severed wires available from Volvo for under 4 bucks, part number 979040, so I can do a gender change on the new harness. Apparently they are still using these same 2 pin connectors on 2019 V90's!!

[RickHaleParker]

Okay, I got the wiring harness (9442158) and it has 2 male plugs on it,

I think they sent you the wrong harness. Is it marked 9442158? Fitment for 9442158 is: 850 1994 - 1997.

[850oldschool]

Clearly marked with the proper part number. Here I applied a filter to the relevant area of the picture they have at www.volvopartswebstore.com so you can see the connectors better, and also enlarged the relevant area of the parts diagram(#31). The connectors are male, just like the knock sensors themselves.

[erikv11]

Oh it is the right part. Part number 31 is to adapt an old wiring harness (two female plugs) to a new knock sensor (one male plug, part 30). It is of course not a replacement for a bad harness, you'd need a whole new harness for that. Maybe you found your way out of things with the adapter but such is the risk with a google-based approach to things. Wish I had paid attention to the other posts about what you actually need, sorry about that.

But that "long" trip to the junk yard would have officially been worth it by now!

[850oldschool]

I'm really not sure what you're supposed to use 31 for. The Bosch 0 261 231 046 discrete knock sensors look like the picture below, with male connectors. Maybe in the early years there were knock sensors with female 2 pin connectors?

The part number (1270492) associated with 30 (pair of knock sensors with wiring loom) on the diagram looks a bit different from the drawing. 31 has a 3 pin female JPT connector, while 30 has a 3 pin male JPT connector.

The good news is that the online Volvo OEM parts sellers have the proper female 2 pin JPT connector (979040) brand new for under $4, so I don't have to spend an hour driving to and from the junkyard to get one, I can just get it delivered to my door, and I can repair my existing wiring.

[erikv11]

Pretty sure the knock sensors didn't change across early P80 cars. They are just simple lo-tech microphones. Been too long (thankfully) since I was pulling lots of intake manifolds, I don't recall ever seeing a difference.

But sounds like you're on it! Let us know what finally fixes it, surely others will run into this problem at some point.

[RickHaleParker]

The good news is that the online Volvo OEM parts sellers have the proper female 2 pin JPT connector (979040) brand new for under $4

979040 is the plastic housing, it may or may not come with pins (978261) ans seals (970772).
Did you check the other end of the harness to make sure it will connect?
Is there a part number on the Knock sensors that are on the car?