Testing NEW EGR Valve

[Rory]

I have to get the EGR system working on my 1979 231 V6 to pass state emission testing. I just purchased a new EGR valve from NAPA. On the car was a NAPA EGR valve installed years ago but the vacuum to it was never hooked up since the TVS was faulty. The brand new EGR valve fails a test by a hand held vacuum pump and so does the previous valve that was just removed and never hooked up to vacuum. Each EGR valve leaks down immediately and I can hear the vaccum leaking out. I read in a different post here that some are supposed to leak when good. How can I tell if that is the case with these ?

 

[Clone TIE Pilot]

Sounds like you may be dealing with a positive backpressure egr valve. This type of egr valve requires exhasut backpressure to close. You can't just test them with a Mityvac like most other types of egr valves.

 

[Rory]

Sounds like you may be dealing with a positive backpressure egr valve. This type of egr valve requires exhasut backpressure to close. You can't just test them with a Mityvac like most other types of egr valves.

Thank you for the information. I am sure you are totally correct.

 

[ELCAM]

From 1978 CSM.

 

[Rory]

From 1978 CSM.

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Thank you very much.