Help-Mystery Vavuum line not Connected

Johns86_944 · 09-13-2002, 06:27 PM

Well, I found this vacuum line that lies next to the battery on my 86 944 turbo and looks like it should continue on through the firewall to something but doesn't. It is a hard plastic line that comes off the 1/2" line going to the brake booster, has a liitle plastic valve of some sort (this valve must be some sort of one way valve??? it makes a funny vibrating noise too) then continies along the firewall and passes through next to the battery but is cut off. One mechanic looked at it and said he thought it should go through the firewall then down to the control box by the passenger's feet, but I looked and that line is hooked up fine and runs through the firewall to the intake manafold like it should. The only diagram I have is the one plastered under the hood; Haynes doesn't have anything in it.

Please Help!!!

Thanks!!!

John

Lawrence Coppari · 09-14-2002, 07:26 AM

There should be a vacuum element mounted on the passenger side of the blower intake close to the battery. It controls the fresh air flaps.

I could photograph mine if you like and email you the picture.

Johns86_944 · 09-14-2002, 03:23 PM

The vacuum element that is next to the battery, tucked up under the thin plastic cowel cover and appears to actuate the fresh air intake, has a rubber hose attached that runs off under the cover towards the drivers side so I don't think that is it.

This one is the hard plastic type and the area under the passenger dash, there appears to be a rubber grommeted hole in the firewall that it maybe is headed for but it is just cut off right next to the battery.

I looked up under the dash but did not see anything that looked like it needed vacuum. Did notice a few loose wires though and a big black box bolted right in my way under the glove box that appears to be an alarm system, disconnected. don't know if this is factory or not.

Any ideas??

John

Lawrence Coppari · 09-15-2002, 05:28 AM

Is the plastic hose white in color? Does it go to the DME? My turbo has one but it is a pressure input for the DME.

Johns86_944 · 09-15-2002, 06:21 AM

Boy I wish I had a digital camera!

The line is dark brown, hard plastic and the same sort as the ones that go to many other components such as the BOV and Throttle body.

I believe the white one that goes to the DME (thats the computer box by the passengers feet on the outboard side right?) is the only whitish colored line (mine has a little stripe I think) I see. It is slightly larger in diameter than the line I am being stumped by. It also goes through the firewall lower down and does not enter into the battery tray area. It appears to be secure at both ends, one at the manifold and the other at the outbord side of the outermost box, which I am taking is the DME.

This line that is giving me trouble is connected at one end to a T off the brake booster's 1/2" line, at which point there is a small plastic valve about an inch long and 3/4" diameter. The line then proceeds along the back of the engine compartment with the other lines and wires then goes through a hole by itself, only to end between the battery and the freah air/wipers stuff. It looks for all the world like it should continue through a grommeted hole to under the dash somewhere but I don't see anything under there. Unless its not supposed to cross through to the battery compartment at all and I should be looking in the engine bay.

Again the car is a 86 turbo. It also has cruise control, which might require some additional vacuum lines than standard, but the cruise seems to work fine.

Car seems to run and drive fine despite this and a small air leak and the cycling valve, though the only thing I have to compare it to is my thrashed NA that has 250,000 mile on it (runs great though!!!)

Any one out there have a schematic of the vaccum system?

John

Lawrence Coppari · 09-15-2002, 07:38 AM

Do you have a vacuum canister by your battery? I have a small vacuum line in the battery area that goes to a cannister. Mine is an '86 turbo as well.

Cruise is completely electric.

Want me to photograph cannister/battery area?

Johns86_944 · 09-15-2002, 02:53 PM

I dont see any canister in the battery area. Please, if you could take a picture that would be great.

Thanks!

John

Lawrence Coppari · 09-16-2002, 02:37 AM

I'm at work now. Will do it tonight unless someone else gets to it sooner.

kenny · 09-16-2002, 04:27 AM

speaking of that thin plastic coweling -- is it available some place (Pelican? -- I tried they couldn't figure out what I was talking aobut) -- mine has a couple of cracks -- it looks like it would be cheap to vacuum-form.

Lawrence Coppari · 09-16-2002, 12:01 PM

Here it is:

Johns86_944 · 09-18-2002, 06:14 PM

Thanks Lawrence,

I have no vacuum canister. The line comes in right next to where the battery cable is bolted to the body then ends. i see a sort of bracket there where something could have attached. Very strange, who would remove the vacuum canister and to what end? The line was not even plugged! I would have never figured that out without those pics. The car is in excellent near original shape and I don't know of any reason to remove that thing, do you?

John

Lawrence Coppari · 09-19-2002, 05:50 AM

Don't know why anyone would remove it and definitely don't know why they would not plug it after removing it.

Off to Road Atlanta with BMW for 3 days. Varrrrrroooooommm!