vacuum lines help

[9dreizig]

Geez seems like I start a new thread once a day..

So I've ripped out the air pump , solonoids etc and now need to figure out the vacuum line scheme.. My 86 disti has two vacuum line inputs..
Does anyone have any suggestions ? I assume the rest of the lines get blocked off ?

[sand_man]

does this help?

[9dreizig]

Thanks Sandman,, but my distributor has TWO outlets and I"m trying to figure out what to do with the extra vacuum lines and where to route the existing ones..

[x98boardwell]

I know that they are for the vacuum advance and retard and they are most affected on cold start up I think. Not sure if this helps, but at least your back on top.

Sorry I cannot offer more advice.

Bryan

[A930Rocket]

if you follow sandmans diagram, there is vacuum line that goes from the vacuum advance canister on the dizzy to #7, the thermo valve and then the throttle body. Connect it directly from the dizzy go the throttle body, above the butterfly valve.

For the other one off the dizzy, I ran it directly to a thermo coupling right in front of the crankcase breather. Basically what it was doing before, but with out any stops.

Everything else gets plugged.

I'm on my iPhone or post a picture.

[9dreizig]

Thanks 930,, say where is Mt Pleasant SC ? My parents live in Lake Lure N.C

[A930Rocket]

Mount Pleasant is just over the Cooper River, north of Charleston.

Originally Posted by 9dreizig

Thanks 930,, say where is Mt Pleasant SC ? My parents live in Lake Lure N.C

[billjam]

Originally Posted by 9dreizig

Thanks Sandman,, but my distributor has TWO outlets and I"m trying to figure out what to do with the extra vacuum lines and where to route the existing ones..

Sandman should have looked over the page! Sorry about the crappy quality of the copy, but at least you can see where the dizzy vacuum lines should run.

Does anyone know what effect item 9 has? It has been blanked off on my car.

[9dreizig]

Thanks Billjam, my 86 doesn't have that either, never did from what I can tell but it's not a Californial car!!!

[NathanUK]

If you are still not sure about the dizzy hoses I can check for you, just ask.
On my car one hose is red, the other blue. They are slightly different diameters which helps to identify where they go too.

[9dreizig]

Thanks Nathan I'm OK I think,, I am still waiting for the injector I ordered from DC automotive to arrive ( $25 used) and am anxious to fire it up again..

[A930Rocket]

My 87 had that. I believe it's part of the emissions. When I re-ran my vacuum lines, I removed that and ran a continuous line from the dizzy to where that part leads to.

[JFairman]

The vacuum solenoid in the vacuum retard line disconnects vacuum retard for a short time after a cold start so ignition timing is advanced for around 40 seconds.
That helps raise the idle speed along with the cold start throttle bypass valve during a cold start.
You can hear the engine drop in revs during warmup when the solenoid opens allowing vacuum retard at idle, pulling the idle ignition timing back a bit.
The throttlebody air bypass valve is also slowly closing but not as abrupt.

It may also do something at full throttle via the throttle position switch during boost retard.

[Helmsy]

I have been having problems with CP's and scratching my head checking lines and blaming the WUR however one of the symptoms is that during warmup and cold startup it idles low (about 400-500rpms) but idles perfectly when warm/hot.

I am now thinking that I should check the vacuum solenoid and dizzy advance/retard module for malfunction and air leaks.

I also have the thing is your #9 pic but there is a 3rd variation. See Euro vacuum diagram:





Is there something else which could cause the revs to be really low until the engine is hot then idle fine (about 900rpm).

The other symptom is mild bucking at slight throttle and the occasional small miss when accelerating after maintaining throttle position but this will entail a whole new thread so I won't hijack this one.

[JFairman]

"Is there something else which could cause the revs to be really low until the engine is hot then idle fine (about 900rpm)"

Yes, if the throttle bypass valve #4 in your diagram is not opening when the motor is cold then your idle will be real slow like you say.
Take the hose off the inlet side and look in to see if the slide valve is open or closed when cold. There is a slot in the valve too.
The valve is opened or closed by a bi-metallic spring. There is a heating element to gradually heat up the spring and open the valve slowly when the fuel pumps are running.
It may just need a little WD40 sprayed in there to free it up or it may be shot.

There is a valve made that is manually controlled that you could put in place there for testing. You can also hook up a long generic choke cable to it so you can operate it manually from the inside of the car.
I've done that on L-jetronic BMW's because the cold start throttle body air bypass really makes the old L-jetronic big 6 cylinder BMW's rev annoyingly high when cold and for way too long.
It is the black plastic heater valve for a water cooled 944 or BMW 320i.
It has the same size hose connections as the aux air valve or throttle bypass valve on CIS. Installed correctly it will work perfectly for this if you want to do that.

Even cheaper and made of metal, is to put a ball valve there with the correct size hose fittings screwed into it. You can make one of those up for about $5-$8 at harbor freight tools.
Some crazy ideas, but they do work...

[Helmsy]

Thanks Fairman.

I will check this weekend. My dizzy also has 2 lines even though I have a euro system so I think i need to follow and check my vacuum lines to see where they go and also make sure none are leaking.

Also what do #12 and #14 do in the Euro pic above? As I have no air pump my #13 is just connected to the valve houseing (bov). Can I just eliminate #13 and plug the housing?

[JFairman]

I found my red fabric covered vacuum advance line dry rotted and blown off of the thermal switch behind and under the CIS unit when I removed it recently, so I had no vacuum advance and didn't know it for a while.

#12 is vacuum operated diverter valve.
#13 is a 12 volt vacuum solenoid valve.
#14 is a large check valve.
All of these parts are for the air pump system only and can be removed if you're not using that.

You can use the vacuum solenoid for other things.