I have a 92 Sl2, 5 speed and the car boggs at 1500 to 2000 rpms, it is really annoying now when releasing the clutch when I am in first gear to get going, it boggs..

I think it is the EGR valve doing this, when I raise the idle it boggs but when I disconnect the vacuum line from the EGR it is fine. And when I raise the idle with the hose disconnected it is fine but when I connect the hose while the idle is up, it boggs and runs rough..I tried this with another EGR valve I got from the junkyard and does the same thing, I cleaned out both EGR valves and the diaphram moves and down. I also replaced the EGR solenoid. There is vacuum from the solenoid when I raise the throttle, so the solenoid is good.

Is my EGR valve bad? I do not see how the valve can be bad, is there something internal that could be bad? The diaphram moves easy, so I think it is good, but when it is on the car connected it boggs at 1500 rpms..I do not want to buy a new EGR valve and the bogging still happens..Driving the car like this is really annoying..What do you guys think?