[cfiiman]

Hey guys...I did a search on here and found a post where someone told how to test the EGR valve...He said you attach a vaccum hose to it, with the engine off, and suck and the diaphram should move and then you hold the vaccum and make sure it stays in place...Well I sucked on mine (quit laughing), and nothing moves...I don't feel any resistance what so ever, just like sucking through a hose attached to nothing...The diaphram doesn't move, nothing...Also the vaccum hose that was attached to my EGR valve I can't feel any vaccum coming from it when the car is running...This hose runs over to some small black box thing on the passenger side back side fender well...Any help with this will be appreciated as I am trying to get my car running right, it has a s/c and I believe this EGR is just adding to surging/bucking/heat problems, or at least it certainly isn't helping things I would imagine...Please let me know what to do...Thanks,

Jason

 

[meangreen92]

...This hose runs over to some small black box thing on the passenger side back side fender well...Jason

Sure thing, Bro'. The EGR valve gets its vacuum from the EVR solenoid(that black thing), which gets its vacuum from the intake manifold. The EVR is just a valve which opens to supply vacuum, and closes to interupt vacuum to the EGR valve. It does this, in response to what EEC tells it to do. The smog pump system works off the same arrangement(the two smaller solenoids).
The EGR valve should hold vacuum, and you should hear it opening. It shouldn't be getting any vacuum at idle though. You can try pulling a vacuum on it, while the motor is idleing, and the motor will stumble - provided that the valve is good, and the passages are clear.
That might just be your problem. If the valve hasn't worked in a while, then the EGR spacer, and intake passages might be clogged with crud, mine were, though my EGR valve was still good. My EVR was clogged too. I simply applied voltage to open it up, and blew through it. It's a pretty easy fix, except for shelling out for the new EGR valve...:sosad:

 

[cfiiman]

So what about when I was suking on the vaccum line attached to the valve and nothing moved and there was no resistance at all like I couldn't "build" any vaccum by doing that...What does this mean?...Thanks for all your help...Oh and how does the evr get vaccum from the manifold...which line supplies the vaccum????...I only know of two coing out of the back one runs to FPR the other runs over in that general direction, it runs into the harness but I broke that so now it just runs to another plastic line that use to be in the harness....

Jason

 

[cfiiman]

And what about checking it at rpm...you said it opens to apply vaccum...How do I check this..by reving the engine????

 

[meangreen92]

I think your EGR valve is toast. Sounds like the diaphram is ruptured. It should be fully opened with less than a drag off of a cigarette. You shouldn't be able to suck much air out of it. If you suck on the vacuum port on the EGR valve, with the motor idleing, the motor should stumble or stall.
Coming from the manifold, you should have the FPR, and another line running to the pass side, which goes to the emission controls. Those vacuum harnesses are all brittle and broken. You should get a vacuum schematic, and replace the harness with rubber hose and tees from the parts store. I wouldn't worry as much about the smog pump stuff, as I would about the EGR system.

 

[meangreen92]

And what about checking it at rpm...you said it opens to apply vaccum...How do I check this..by reving the engine????

What I did with mine, was to disconnect those solenoids, and remove them from the car. I then used a common 9V battery, and my mouth, to test them. They shouldn't let any, (well, maybe just a little) air through them without voltage. When you apply voltage, it should open and allow air to flow through. You can check them electricly, for resistance, but you really want to blow through them, while toggling the voltage, to make sure that they are opening and closing. My TAB and TAD(the two smaller ones) looked like water froze in them, they were junk. I got some replacements out of a Town Car at the junkyard. My EVR had like sand in it, but I got it working again. Mine all leak a little air when not powered up, but you can definitely notice a big difference between opened and closed.

 

[cfiiman]

Thanks I'll have to look into this whole thing