anyone know what, if anything, connects to where the "B" is?? this isn't my pic but i have the same setup. i noticed that the solenoid has 4 holes. 2 for the L shaped connector to the vacuum lines, and 2 more at the back. checkin my solenoid for a code 32 i noticed that it wont hold vacuum, but when i put my finger over "B", it holds. i'm thinkin this could be the problem because the little metal clip looks like a safety for a hose that used to be there.

 

Is that the EGR vacuum control valve? I think it is. If so, then, no, nothing connects there. That valve is under ECM control (the 2-prong electrical connector). The valve either routes vacuum on to the EGR valve or vents it to atmospheric to vary how far the EGR valve opens. It's works on a "duty cycle" priniciple kinda like a fuel injector. 0% open time, 25% open time, 100% open time, etc to send an "average" vacuum signal to the EGR valve diaphragm and control it's opening.

It's default, if not connected to the ECM is to vent all vacuum to the atmospere- the open hose end. There is usually a little foam filter on there to prevent sucking in dust but it's usually long gone on cars as old as ours.

If your car still has a fuctional EGR system and the chip is still programmed to run the EGR valve you can watch the EGR duty cycle variable change on a scan tool. It usually is 0% except during part throttle conditions.

 

ok i thought something was connected there. i hooked up a hose to that fitting and plugged it, drove it but the SES light still came back on. so when i got back home i took it off. then i removed the solenoid connector with the ALDL grounded and hooked up a test light to it. it lights. so the ECM is controlling it. then with the ALDL grounded and not grounded i supplied vacuum to the TB side of the solenoid. it wouldn't hold. i'm guessing this is a bad solenoid?

i also removed the plenum to remove the valve but the damn bolts feel frozen. i tested the valve with vacuum too and the diaphgram moves and holds.

 

ttt

 

The diagnostic steps for a TPI engine are slightly different:

 

thanx. but it'll be hard to check the movement of the valve when i can't even get a mirror in there. I'm gonna try and loosen up the EGR bolts too and try to clean up the passages under the valve.