Draj

My 94 E320 got rear ended recently and was unfortunately totaled by insurance company. I purchased another 94 E320. During test runs, I got a check engine - code 5 which is EGR inoperative. The seller's mechanic told me that the EGR is fine and to run it some more to see if it appears. He also told that they repalced the water pump and radiator recently.

Last weekend, I got the same code again. Looking under the hood, I noticed something strange. The EGR switchover valve is a dual one - EGR and air injection. In alldata they show the bottom of the 2 valves as EGR and the top one as Air injection. In my car, it is reverse - the EGR is hooked upto the top valve and the air injection to the bottom (with appropriate wiring connection). Is this wrong? Does it make a difference? Can someone tell me if the the line from EGR should be connected to the top or bottom valve?.

I would appreciate any help you can give me. Thanks.

hineywineries

I'm shootin from the hip here, because I am at home. I'd try connecting it like Some-Data says. I'd also take a careful look at the vacuum line and connections to and from the EZL module. That vacuum lines controls or affects EGR. I'm assuming you have the M104 engine.

bicylindrico

I believe "alldata" is wrong. Imagine that. You will see the vacuum line exit the upper switch-over valve and connect to a metal line and head for the EGR valve. The lower will have a redish vacuum line that connects to the Air inj. diverter valve. The harness is pretty much configured to plug in one way with the leads being different lengths. The EGR line from the valve to the intake were prone to plugging up with mileage over 100k.
An easy check would be to pull a vacuum on the EGR valve with the engine running. The engine should start running very bad. A slight change or no change will signal that the line may be plugged. Just remove and clean out with an old speedo cable or coat hanger. I hope this helps.

bicylindrico

I'm sorry Hineywineries, that car doesn't even have an EZL. The vacuum source for the switch-over valves is from the intake manifold just behind the P/S pump. The connection is shared by the fuel pressure regulator.

Draj

Thanks a lot for both your replies. I think you are right in suspecting "alldata" to be wrong. Steve Brotherton in his article says that "often the vacuum lines to the switchover valve at the front of the motor get switched" and you get a check engine. http://www.continentalimports.com/ser_ic100345.html

I will try to the test bicylindrico suggests and let you know. Thanks again.