View Full Version : Need help with vacuum lines

08-31-2004, 08:29 AM
After pulling the engine apart and putting it back together, I had to guess where all my vacuum hoses go. I think I got them all figured out, except I can't find anything that goes on the supercharger bypass valve. Can someone describe which line goes to it? The vacuum diagram on the car doesn't even seem to have this line listed. Depending on if it's a line I already have going to something else, I may have to ask about other lines as well.

08-31-2004, 10:47 AM
On my 90 - The line is one of those hard plastic type.
The end on the bypass valve is a preformed rubber 90 attached to the line. The other end has a preformed rubber fitting which attaches to a large rubber 90 near the master cylinder. Line with blue tape in pic.
I attached a couple pics if they came out.
Hope this helps

08-31-2004, 07:07 PM
Okay, I managed to find another line that was hidden down around the transmission. It has a 90 degree elbow, like the one in your pic. However, there was already another line with a 90 degree elbow coming from the driver's side. I'm guessing one is the red or yellow line in your pic. Since all of mine are 90's, let me describe where they go and make sure I have it right.

First, one goes behind the brake cylinder and ends up at a device next to the clutch fluid reservoir. For those with automatics, it's at the back of the firewall on the fender behind the shock tower. I'm guessing this one goes to the blower bypass. The second one goes behind the brake cylinder also, but I can't tell where it ends up because it goes behind other lines. I'm guessing it goes into the firewall. This must be either the red or yellow line, whichever the fuel pressure regulator line doesn't reach. And then the FPR is the third. If I can just verify where the first line goes to, I should be able to figure out the others.

Thanks for the help. I should learn to label these lines, though after this, I'll probably have them memorized.

09-01-2004, 02:01 AM
Breakdown of vacuum lines.

1. pcv to back of inlet plenum. also breaks to pass side front of car.
2. back of inlet plenum to dist. tee below wiper cowl on firewall/cowl
3. return plenum to firewall (drivers side) for boost gauge
4. inlet plenum to vacuum actuator for boost releif
5. inlet plenum to return plenum
6. return plenum Tee from #5 to drivers side ( has circular disk by brake booster)
7. firewall/cowl tee to pass. side for heater controls vacuum
8. red/green hoses for egr. green to egr valve, and red to return plenum or firewall tee? not 100% on that one.

Going off of memory here. Had that friggin stuff appart so much, just kinda know where it goes.

09-02-2004, 05:27 AM
Thanks. I was confused at first because there's no way the bypass valve could connect directly to the inlet plenum; I don't have a line for that and there's no nipple. However, I saw in another post that on earlier models, it connects through a solenoid first, the device I described earlier. The other line I was talking about must be for the guage, which should obviously go on the return plenum. I believe I have everything figured out now.