Need help with vacuum
 

Could someone please show me exactly which ports on the throttle body you connect the vacuum advance and retard to on an 82 five speed? I need to make sure I have them right.

Mine idles and revs perfectly with the VA plugged, but cuts off with it connected.

It is not drive able with it disconnected, looses all power when accelerating under load.

I replaced the vacuum advance, with no joy.

Please help. This is driving me insane!

Thanks

I have asked several times on the forum, for just a picture of someone's, or a drawing....I have been through the WSM on my iPad about 50 times with not much luck. Finally dug out my printed version, and found what I needed...finally!

Ron,

This is a Rennlist link that documents the ports on the throttle body for the L-Jet '81 - which is what I have. Your '82 *should* be similar, unless you have CIS.

Once and for all: ID of vacuum ports on Throttle - Rennlist Discussion Forums

Thanks...I actually found what I needed I. The WSM, believe it or not...I have it electronic, and couldn't find it...once I flipped through the printed copy, it jumped right out at me!

Leaks
 

I don't have a Diagram but see you found it :)
does That year have the dual Vacume Distributor like my 80 ? . 1 for advance and 1 for retard .
Any-old way here are some tips .
Test the Vacume for holding Vacume on the Distributor make sure they hold Vacume .
Easy Test is suck on it with a " Clean Vac Line attached and leave the Line on your tongue , you well feel it if the Vacume does not hold .

Find All Vacume Leaks , All of them :
with car outside and running at idle just run a garden Hose on low pressure slowly over
all the Vacume lines , Intake Manifold Ports Everywhere that have Vacume .

of course avoid the Injection wiring , Spark plugs wiring Etc .
If you find a leak the motor well slow down , You well note this right away . Water well not hurt the Car .
( been using this trick for many years of all cars )
Porsche 928 16 V Motors well take a lot of advance . Elevation is a factor , I don't know how high China Hill is humm . You can fool around with it advancing until you get Ping on acceleration then back it off about 5 Degrees and try it . Or you can go with the
" Listed " timing specks .
Always Start with a Manual Compression Test ( Screw in Gauge ) they should be within 15 % of each other or better . Should 1 or more be Low add a Little oil to that cylinder and see if it go's up more then 5 LBS . If so the Rings are bad .
Most all 928 Rings are Good due the the Siliconized Bore they last a Very long time or until you drive with no water or Oil lol
Are just a ton of tiny Vacume Lines and places Vacume can leak . But you can find them and when you do with Good Compression you can make it run right .
Don't forget to have Good Ignition , Wires , Cap Plugs and the like

Thanks! I am tight with vacuum...I am back to where I started, except she will now start and run at idle with the vacuum advance and retard connected.

Having a tough go at work, and won't get much time to work on her this month, but I again feel like the cam timing is off....1st chance I get, I will remove the timing covers and see if all the marks line up....I am betting they don't.