1porschenut

I have a 84 928 that I rebuilt the engine in and dont remember where all the vacuum lines go can anyone help me out.

Thanks
Matt

Landseer

This will get you most of the way.

https://rennlist.com/forums/928-foru...983-928-a.html

83 and 84 are identical with respect to vac.

Post again with specific questions if you need more help.

1porschenut

I looked at the diagrams that you refered me to but I'm still not sure it looks like that the three regulator are tie together and go to the throttle body but after that I'm not sure but on my distrubuter I dont have both retard and advance i just have retard if there is more detail pic i would greatly apriceate it.

thanks
Matt

1porschenut

I looked at the diagrams that you refered me to but I'm still not sure it looks like that the three regulator are tie together and go to the throttle body but after that I'm not sure but on my distrubuter I dont have both retard and advance i just have retard if there is more detail pic i would greatly apriceate it.

thanks
Matt

Landseer

I have 2 USA 84 cars here in case we need to look at them.

You should have vac advance, just like mine.


The problem is that the workshop manual diagram for this model is split into at least 3 different, maybe 4 separate diagrams. You really have to study them to get anywhere and its confusing. I did that and tried to show which parts are linked on this diagram. There is no other consolidated diagram that I know of. There needs to be a better guide and some good pictures.

So there are two ports on the back of the throttle body. Number 1 is on the passenger side, Number 2 is on the drivers side by my syntax.

So, that passenger (right) rear nipple provides vac for the distributor advance and also the thermo valve, I think to the angled port on that valve. Its located on the water jacket on the back passenger side. Thats all Number 1 handles.

Number 2, back of throttle body, drivers side, provides vac to the two regulators and the damper and the top small section of the control valve.

It doesn't matter exactly how you run the vac hoses, just that they perform the functions shown.

1porschenut

what about the one on the front if you can take some pic I would appreciate it.

928 obsession

I don't know if this will help, but under the hood there should be a diagram that shows the locations of the vacuum lines.

NoVector

Matt - If you don't have a diagram on the underside of your hood, let me know and I'll take a picture of mine and post it. When I did mine, I took a picture of it, zoomed in, and then printed it--made it a lot easier. That will get you about 90% there. Taking a picture of the hoses would be tuff to do as many are routed under the spider... / Bruce

Landseer

Diagram is within the link on post #2.

Gotta define the rest of the vac ports on the throttle body for him. After some sleep.

1porschenut

I did take a picture of my hood but two things are wrong on when I bought the car it did not have the right hood and two some of the sticker is missing.

1porschenut

On mine I have the spyder off so it is alot easyer to reroute all of the lines.

Landseer

You do realize that the diagram in the link is the 1984 USA sticker.

1porschenut

do I did not thanks for all of the help.

Landseer

The spatial arrangement of the sticker sucks.

BUT, pay attention to the shape of the various components like the control valves I and II. They are correct.

I'll define the other throttle body ports for you in a few minutes, I forget which is which and have to go look.

Got a lot going on this morning for some reason.

1porschenut

thats fine when ever you get a chance and again thank you for all of the help.