ok, can someone tell me what this is, and what it does and hoe to go about fixing it. the wire came unplugged from the back of it and im not sure what to do, the car runs fine, but it does idle low. i just finished this swap so im trying to figure out what to do.
thanks.

 

That almost looks like the coolant sensor connector, although it cant be since its way to close to the alternator connector, If I had to bet id bet oil pressure sensor in which case, to see if thats the correct thing if you put your key into spot 2 if your oil light doesn't come on its your oil sensor lead which is 1 wire.

If I would have a chance at making a 2nd bet I would guess something else around the intake manifold....

btw you didnt make that harness did you?? the whole thing, cause if you did it might be coolant sensor line and thats located on the head on the side where the dizzy is located and is a single wire.

in either case
if its a coolant temp line to the dash or the oil light, it would not under any circumstances make your car idle weird it would simply not allow you to measure coolant temp or let you know if you have oil pressure or not.

 

naw, i didnt build it, it was just the only picture i could find with it displayed clearly

 

ok well if its 1 wire, then its generally only the 2 things ive mentioned.. could be knock? although i dont believe the b1 had knock...

 

If it's round it could be for the oil pressure sensor on the back of the block.

 

yeah its right there on the back of the block.

 

yea, it only one wire, thanks man.
now i gotta figure out why it idling at 600-800, i know my tps sensor is going bad, will that cause it to idle low

 

yup, if it has one wire then it is definitely the oil pressure sensor.