Seems to originate from the alternator but is just hanging there - the grey plug just below the green wire. A diagnostic? Or should it connect to something?

 

It doesn't look very long but see if it reaches to the knock sensor, that's what it seems to be like, and close to it...

 

Hmm - I've been studying wiring diagrams - it looks like not all B230 FT engines received the knock sensor? Specifically, the LH-jetronic 2.4 mutliport system does not (or at least I couldn't find it on the wiring diagram) while the EZ K Distributor system does.

 

Hmm, never faced that... but makes little sense for some engines not to have it while others do (the same maker)... It's pretty basic engineering. But, OK, does your car have the knock sensor? It's easy to check, under the intake manifold.

 

I know - easy to check. But I cannot find it. The green wire next to it, I think, goes to the ECT sensor. But nothing else is in that area. Certainly nothing that the plug I have can reach. So I researched the wiring diagrams and didn't see the knock sensor listed (item 7-24) on the "LH-jetronic 2.4 mutliport system" . But, to be honest, I have no idea what sub-model of the B230 FT engine I have. I didn't even know there were sub-models. Here are the wiring diagrams I have been studying. The knock sensor is also missing on the Regina ignition engine apparently.

VOLVO 940 1993 - wiring diagrams

I'm OK putting this issue to bed. As you know, lev, I'm chasing down a poor engine performance cause on another thread. You've been very helpful to me there. This hanging wire plug probably is not the cause.

 

Yea my turbo (93 940) has this wiring as well, never bothered with it. Its pretty short so nothing close to plug to. Good to know it probably just doesnt have a use.

 

I took some pictures as best I could of the plugs I have in that area. I have a 1990 Volvo 240 with 2.4 as well. Hope this helps!

 

My 92 B230FT has the same wire and it goes nowhere, you can see I have labeled the knock sensor prior to engine removal. I have no idea, don't worry about it.

 

It looks like the wire may be left over from earlier LH fuel injection systems that had a cold start injector. The pic posted by Damiun Walker shows a cold start injector while the other pics don't have one. I believe the cold start injector was removed in the early '90s.