96 850 Turbo - Should a vacuum hose be plugged into this nipple?

bugs11 · Post by **bugs11** » 16 Apr 2016, 21:40

Saw this nipple on the underside of the MAF tube when I was working on the torque bushings today. I've looked at schematics online but can't tell if a vacuum line should be plugged onto this nipple. The black vacuum line in the lower left of the picture comes of the TCV.

Post by **erikv11** » 16 Apr 2016, 22:10

That's the nipple for the line to the metal tube that leads behind the engine and over to the FPR. The intake will get unmetered air through that nipple. And I would expect the FPR won't work right ?

Sommerfeldt · Post by **Sommerfeldt** » 17 Apr 2016, 02:42

erikv11 wrote:That's the nipple for the line to the metal tube that leads behind the engine and over to the FPR. The intake will get unmetered air through that nipple. And I would expect the FPR won't work right ?

I'm not sure that's accurate. On mine, the only vacuum line from that end is the line to the TCV, which is the one not connected to anything in OP's picture (blue labeled vacuum line).

- S

Sommerfeldt · Post by **Sommerfeldt** » 17 Apr 2016, 04:21

Note: Newer models have intake pipes with 3 vacuum nipples on them - one more up by the MAF, and one down by the PTC (not on it, beside it). As long as your intake pipe only has that one nipple up by the MAF, it's definitely the line to the TCV.

- S

gswede · Post by **gswede** » 17 Apr 2016, 05:56

Off the TCV blue port, the hose should go to nipple on the accordian plastic hose. Nipple shown in first picture. On som accordian hoses there are two nipples in this area, right after maf. One should be plugged off, the other, as said, blue line from connector.

Another thing, on some of these accordianhoses, there are two nipples, but one can actually be blocked off.
Take a piece of hose and connect to nipples and confirm which one is open. If both are open, connect blue tcv hose to either one and block off the other.

Sommerfeldt · Post by **Sommerfeldt** » 17 Apr 2016, 06:33

gswede wrote:Off the TCV blue port...

Exactly what I said. Also, the new intake hose has 3 nipples, not 2. The part was merged some time ago, and using a new intake hose on an 850 requires you to block off 2 nipples - one regular size up top by the MAF, and one larger next to the PTC. (Don't block off the vacuum connection on the PTC itself, of course...). The blue (middle) hose from the TCV should be connected to the nipple near the MAF.

- S

gswede · Post by **gswede** » 17 Apr 2016, 06:54

Hmm odd, my new accordian pipe bought from local dealer last summer did only have two ports..
There is of course a vac port on the PTC but that is a alltogehter different matter

Sommerfeldt · Post by **Sommerfeldt** » 17 Apr 2016, 08:03

This : https://www.ipdusa.com/products/7159/11 ... 70-s70-v70
is the part you'll get if you buy a new inlet hose these days. If you check you the pics, there are 2 vacuum ports up top, and beside the PTC, there's another one. Acc. to Volvo, these are a merger of the one for 850s, and the ones for V70s etc. They even have a kit for blocking off the 2 unneeded ports for us 850 people.

- S

Post by **erikv11** » 17 Apr 2016, 11:18

I was assuming OP knows the blue TCV line goes to the snorkel tube, but if not then yes yes yes, that goes to one of the nipples for sure.

OP, check if your car has the skinny metal line running behind the engine, over to a fuel pressure regulator mounted near the steering rack. If it does (it may not), then be sure that metal line connects to one of the nipples on the snorkel tube (intake). Here is a great documentation of that line from jreed, on a 98 https://www.matthewsvolvosite.com/forums ... hp?t=54895.

bugs11 · Post by **bugs11** » 18 Apr 2016, 18:23

Interesting. All the vacuum diagrams I looked at show that center (blue) line coming off the TCV ending in thin air. I plugged the hose into the nipple, see if it makes any difference. There is a skinny steel line running along the firewall but it terminates into the ABS pump.

I'm positive that blue line wasn't connected to the nipple last fall when I tore it all apart to replace the head gasket, but then all the vacuum lines were gone to crap at that time. I replaced any vacuum line or connector, big or small, that looked even slightly suspect.