EGR valve issue
 

Hey all,

I took my 1991 300E to get it's smog, in which the emissions surprisingly passed but it failed the visual test as well as a bad gas cap.

When I had recently changed my distributor cap I guess I put the already disconnected EGR vacuum line out in the open and left it like that. The tester saw this and failed it because no vacuum was going to the EGR valve, he said he would pass me if I fixed it and brought it back. So I finally decided to actually follow the vacuum diagram and try to connect everything as it should be connected. I reconnected everything according to the diagram and vacuum lines that weren't connected before to the switch valves were now connected and all seemed that the the system was 100%. I drove off feeling good, got to a stop sign, stopped then when on the gas, got a 1 second hesitation, feeling like it was going to die out then it went back to normal...

Got to another stop, same thing, right when you go on the gas, it feels like its going to die out but catches itself right before and is fine. I disconnected the EGR valve and no hesitation and the problem goes away :confused: Can anyone point me in the right direction and give me any insight on what could be wrong? Is it a faulty EGR valve? I would think the car should act funny with it disconnected but it was fine, when connected it does this... Any info would be greatly appreciated! Thanks!

It sounds like the EGR valve is open when it shouldn't be. It could be sticking, and a cleaning (or replacement) would help with that. Or it could be getting a signal to open when it shouldn't. That might be a little bit harder to find.

Thanks for the reply... Ugh, hoping it's the first one... I took it off today and have ordered the new part, so hopefully it'll fix the issue. I've read that the pipe can fill up and become clogged with soot, so I stuck a long vacuum hose (only thing I really had) and it felt as though it went all the way to the cylinder head, that's good? or should it go further?