I posted the following on the "engine and exaust" forum but haven't received any response. Maybe someone here can help with my request:

I picked up a '78 280Z at an auction and I am in the process of getting it up and running as it came from the factory. The previous owner replaced and modified the existing EGR valve and neglected to transfer the OEM identification number. Therefore, I am not exactly sure what is installed.

The replacement I purchased requires an orifice washer be installed to regulate the exaust gas into the intake manifold. The vendor supplied about twenty five different orifice washers of various sizes.

If anyone out there, who has a '78 Z (76 or 77) with an original EGR valve, can look and see if they have a number stamped on the unit. The number will look like this: 14710-H9810 or similar. I have a cross reference chart that will tell me what correct size orifice to use based on the OE model number.

Thanks,

Randy

The Microfiche shows up to 7/77 is 14710-N4705 and from 8/77 and up is 14710-N7600 . You should buy the Microfiche from the site the information and blow ups of the parts is worth it alone. Its available here

https://www.classiczcars.com/store/index.php?cPath=2&osCsid=oq7cph8tqhdvajhmsi3ao08gn0

Hope this helps. Jeff

Jeff... You are the man! This is exactly what I was looking for. It appears the previous owner had installed the incorrect EGR valve as I had suspected. With this information I can now install the correct orifice washer.

I will investigate the microfiche you recommend. Thanks again...

Randy

You wouldn't happen to remember the size of that washer that you were trying so hard to determine; would you? I have the same issue now with my '78.

Per my service notes for my '78 (12/77):

"Replaced EGR control valve (14710-N7600) with aftermarket part. Installed #34 orifice washer."

I think I got the aftermarket EGR valve from Black Dragon, but I'm not positive.

As I recall, something about the cross-reference process was clear as mud, but after several phone calls, I did manage to get a definitive answer -- definitely #34.

Edited December 29, 201014 yr by FastWoman