IROCWPB

But after reinstalling the plenum and tightening the hell out of the torx bolts, I can't feel the leak above, but there's still a large vacuum leak in the area, just not enough room to find what it is.

Sounds like it's the big round stamped metal thing that sits right in the middle of the intake manifold (under the plenum), has a vacuum line running to it, the line isn't leaking, but maybe that thing has gone bad?

could be one of the runners where it meets the manifold also, but I'd need to take out the fuel rails to find that. anyone have any ideas on how to find a leak in this tiny little area? spraying carb cleaner in there doesn't seem to effect the idle, but there's a constant hissing that I'd really love to get rid of. Also, it can be heard MUCH louder from the drivers side than the passengers side, not sure if that's at all helpful.

jamon8

iTrader: (3)

put a LITE coating of black rtv on both of the mating surfaces and let it tack up for about 15 min

put it back together with new gaskets


the problem is if it is not idleing higher when you spray it with carb cleaner then you do not have a vaccum leak. you really need to put it on heavy though- no light misting

the piece that you are talking about under the upper pleneum is the egr valve- I would just replace it because of its low cost and pain in the butt factor when it goes bad. there are ways to test it with a vaccum gauge

there is a little number on it that you will need to give to the parts store.

there is a little hose on the bottom of the throttle body that could be causeing all your sucking noise. its part of the vaccum harness the runs under the upper pleneum

IROCWPB

I got very intimate with my throttle body and plenum a few hours ago and I can't for the life of me figure out what you're referring to when you say little hose on the bottom of the throttle body. there's the PCV port, coolant in and out, tps and iac, and one vacuum port under the PCV port. Am I missing something?

The sound is definitely coming from the middle to rear, underside of the plenum though, well away from the throttle body.

jamon8

iTrader: (3)

there should be a hard vaccum line that goes from the back of the fuel rail coming off the pcv purge valve that goes to the bottom of the throttle body

it runs almost the whole lenth of the intake

IROCWPB

Where exactly on the TB does it hook up to? You said the bottom of the TB earlier. I was attempting to open up the IAC compartment there but the torx screws were too rusted to be removed without stripping the heads or breaking them. Anyway, the only ports on the bottom of my TB are a coolant passage and where the IAC screws in.

Just realized you're in southern IL. I was up in Carbondale a few weeks ago. What city you in? Also, you have my sympathy.

ploegi

Under the bottom of the throttle body, toward the drivers side. Also, if you can hear something toward the middle/back of the plenum, is the IAT sensor in there? That would be a handy vacuum leak.

IROCWPB

That the sensor that's mounted to the underside of the plenum? yeah, it's there.

IROCWPB

Just found the vacuum port that jamon was referring to. It's never been hooked up to anything, unfortunately it's not the vacuum leak I've been hearing, the one I've been hearing is much much bigger. Can you guys help me to figure out where the vacuum port on the bottom of the TB hooks up to? as far as I knew, and I studied my vacuum system to get my AC controls back online, my vacuum system was all hooked up properly.

So I need to run a hose from this TB port to where???

near the back of my passenger side fuel rail, there's a rubber piece that plugs into the bottom of the distributor i think? there's two vacuum hoses plugged into that already. Both ports on the rear of the plenum are occupied also. I found a two way check valve and hooked my AC controls back up with that, the other side of it goes to the power orb.

What does this vacuum port on the TB control? the EGR solenoid or valve? how has this being unhooked effected my car?

THANKS GUYS! I'll get this thing back in shape one of these days!


edit: there's two vacuum lines going through the firewall, one's for the AC, i forget what the other is for but that's plugged, I think it may have been a part of the AIR system I removed from the car?

IROCWPB

bump. someone help me figure out where to hook up this vacuum line?

jamon8

iTrader: (3)

there is a purge valve by the left rear of the intake manifold

it has two lines coming off it. one goes to the throttle body and one goes to the egr valve

so if the vaccum line is still hooked up to the egr valve follow it back to the purge valve and you should see that second line or you will see an open port where a plastic hose should be

good luck

IROCWPB

The EGR Valve is hooked into one of the two ports, the other port is hooked up to the valve that goes to the charcoal canister.

If the vacuum port on the bottom of the throttle body is supposed to be hooked into one of those ports, where does the charcoal canister valve vacuum line get hooked up to? I'm hoping to get this corrected today so any help is greatly appreciated.

I've been getting a code 34 when I start up my car when it's cold. I'd like to think that this is the cause.


edit: Some pictures just so there's no confusion about what I'm talking about:
http://i79.photobucket.com/albums/j1...B/dscn0282.jpg Think this is called the EGR Purge Valve?
http://i79.photobucket.com/albums/j1...B/dscn0283.jpg Connections to Charcoal Canister Valve.

IROCWPB

I hooked the throttle body port to the EGR Solenoid, I'm still throwing a code 34 however, I'll be replacing the EGR Valve next. Also, the tank pressure control valve no longer has vacuum, I guess it never did being that it was hooked to the EGR solenoid. Can I run straight tubing without a valve from my fuel tank line to the canister to the throttle body with no valve? I'm thinking that'd make a vacuum leak, but I don't know where to get vacuum from for that valve.