Vacuum loss..

Prospeeder · January 16, 2006, 06:42:02 PM

Im still having the vacuum loss under boost and what not for the HVAC. I took the checkvalve off and blew in it and it did exactly what its suppose to, suck but not blow, so boost doesnt get in, and i took off the line to the Vacuum cansiter,and it hissed and held pressure just fine when i sucked or blew into it, no loss or anything, same with the cruse and HVAC i suck and its tight, not leaking, BUT the one that goes from the check valve to somewhere behind the plenum, i can blow/suck freely as if theres a leak, is it suppose to be that way?

And no Blow/Suck jokes please :lol:

GangstGP · January 16, 2006, 10:17:37 PM

I hate that one ,it always breaks

z284pwr · January 17, 2006, 12:16:43 AM

Make your own boost leak tester to locate it. We just took a PVC plastic cap, use an air fitting on it, and used the stock tube that went to the air filter. It works great

Prospeeder · January 18, 2006, 08:36:45 PM

i dont have a boost leak, just the HVAC goes to the floor when under boost, is the one from the checkvalve to the back of the plenum suppose to be sealed so i cant blow in it or what?

z284pwr · January 18, 2006, 09:40:50 PM

There should be no vacuum source on the back of the plenum, it should be plugged, that is where the vacuum brakes tap into. If its under boost, its a boost leak :P

Do this, just unplug every vacuum line except the FPR and MAP sensor, they are the only 2 absolutely necessary ones, start eliminating possibilities to locate the problem

Prospeeder · January 19, 2006, 02:56:27 PM

ok, so if its not a vacuum source, it should be "plugged" and not able to be sucked or blown into?

z284pwr · January 19, 2006, 03:14:55 PM

Quote from: Prospeederok, so if its not a vacuum source, it should be "plugged" and not able to be sucked or blown into?

Umm, if we are on the right page and talking about the right thing here, then no, it shouldn't, because well, its a big hole in the back of the plenum that has a screwed in metal plug.

Edit, that is if it is un messed with of course. Mine has a T valve for the BOV and Boost Gauge in it

GangstGP · January 19, 2006, 03:22:38 PM

:lol: :lol: :lol: :lol: quit messin with speeder, he dont have nothin there yet! :lol: :lol: yes it should be pluged if its not in use. if there is an open hole anywhere nothing works right and the hvac will not work right. and the cruise wont work right. you can usually tell where the vac leak is just by driving and seeing what works. If you work on them enough that is and you see where the leaks pop up. You can actually get pretty skilled at it, the more it happens.

Prospeeder · January 19, 2006, 09:50:04 PM

Ic ic, my crusie and hvac work fine untill you get under some boost, so it should be plugged, ill have to check that out i guess, I HAD a picture bossman made but its off his server now, little ghetto drawing but it helped imensly

LukeZ34 · January 19, 2006, 10:52:53 PM

Ok, let me get this straight..
The line that you can blow in to with no resistance is the one attached TO the check valve for the Cruise and Hvac system?

If so, that connects to a hose behind the plenum, which then runs under the plenum and around the front to the Throttlebody. It's NOT the line that goes to the Fuel pressure regulator and MAP sensor, it's the other one. There's a connection behind the plenum in which that line connects to. Grab a flashlight, and dig around behind it, you should be able to find it, and when you do, make sure it has a tight fit. Any loose fitting vacuum lines on a boosted car can be a problem since the boost can push them apart.

Prospeeder · January 20, 2006, 08:04:41 AM

No, it Doesnt from the TB, it its the 3rd line on the Check valve, ill take a pic, it goes from the Checkvalve for the hvac and cruise and off behind the plenum

IN green, i have a screwed up vacuum system dont i?

z284pwr · January 20, 2006, 09:35:12 AM

Quote from: ProspeederNo, it Doesnt from the TB, it its the 3rd line on the Check valve, ill take a pic, it goes from the Checkvalve for the hvac and cruise and off behind the plenum

IN green, i have a screwed up vacuum system dont i?

[/img]http://img.photobucket.com/albums/v210/Prospeeder/TB.jpg[/img]

Going off your picture, yeah I would say so, why do you have 2 vacuum sources going to the same thing? :? Especially considering a check valve probably probably won't work very well when the bleed side of the check valve is also being pressurized.

and 3rd of TB line, does that mean from the front to back or back to front?

Front to back should be what FPR and MAP, HVAC, Purge, and EGR

LukeZ34 · January 20, 2006, 09:50:51 AM

Quote from: z284pwr

Front to back should be what FPR and MAP, HVAC, Purge, and EGR

Yea, that's correct.
Judging by the picture, the green line you have problems with shouldn't even be there. The Cruise and canister come off one port on the check valve, and the Hvac comes off the other port.

I'll have to look at ours when I leave for lunch.

z284pwr · January 20, 2006, 02:26:17 PM

Quote from: LukeZ34
Quote from: z284pwr

Front to back should be what FPR and MAP, HVAC, Purge, and EGR

Yea, that's correct.
Judging by the picture, the green line you have problems with shouldn't even be there. The Cruise and canister come off one port on the check valve, and the Hvac comes off the other port.

I'll have to look at ours when I leave for lunch.

Yeah that is correct, the Purge is the big fat vacuum line. The Cruise is in with the HVAC one. You definitely shouldn't have that green one plugged into the back of the plenum

GangstGP · January 20, 2006, 03:59:38 PM

yea he should, that line is supposed to go on the back of the plenum underneath where the plug most of us take out to put our BOVs on. It leads to the check valve under the cruise unit. I think the cruise plugs in on the next tee down the line.