EGR Solenoid California Emission 1985 305

[kismetsdad]

I just acquired this truck and am sorting it out. It is completely stock. It failed smog in California and when I started looking at all the vacuum lines I found most of the plastic vacuum lines brittle and cracked and I was unable to figure out what went where. The vacuum map on the Frame is pretty good but the routing of vacuum to the EGR solenoid is a bit of a mystery. The3 ports of the solenoid go to the EGR valve, Port "J" of the Carb, and Port "F" of the carb. After many hours of search I have learned that only the 1985 and 1986 CA EGR valve has 3 ports where most have only 2. For the sake of explanation call the ports "A" ,"B", and "C". I pulled the solenoid and tested it. When the solenoid is inactivated port "A" to "B" is open. When the solenoid is activated port "B" to "C" is activated. The vacuum map is below. My best guess is that when the solenoid is activated vacuum from carb port "J" (on map) is applied to solenoid. Furthermore is am guessing that when the solenoid is inactivated the EGR vents (or unvacuums) from port "F". Carb "J" is manifold Vacuum and Carb "F" is more of less atmospheric at top of carb

I have searched high and low and can not get an answer to which ports on the solenoid (picture enclosed) go where. On other words: which ports go to "F", "J", and the EGR.

The EGR solenoid has 2 barbed fittings and 1 smooth fitting

Thanks in advance

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Th

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[Goldie Driver]

I'd mimic the way your schematic is drawn with the hoses.

So, upper right port is vacuum from the back of the carb.

Lower right to the EGR, and the port on the left to the front of the carb.

Might just work.

 

[kismetsdad]

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After replacing all the vacuum hoses I booked an hour of diagnostics with the smog shop and the truck passed smog cleanly. The EGR solenoid vacuum routing confirmed by the techs at the smog shop is as above. "F" as denoted in the vacuum map is not barbed and always subject to clean, filtered atmospheric pressure. The barbed fittings go to EGR and "J" which is manifold vacuum. When the solenoid is activated manifold vacuum "J" is applied to the EGR. When the solenoid is deactivated the EGR vents (technically un-vents) to atmospheric pressure port "F" at the carb. As I noted in the initial post this EGR solenoid only applies to California emission vehicles in years 1985 and 1986.

 

[Finkaire]

Just failed smog NOX. EGR valve I removed is aftermarket and has a spacer between the manifold and the valve. My question is: Is the spacer factory or did it come with the aftermarket valve, OE ordered.
Thanks!

 

[Goldie Driver]

Just failed smog NOX. EGR valve I removed is aftermarket and has a spacer between the manifold and the valve. My question is: Is the spacer factory or did it come with the aftermarket valve, OE ordered.
Thanks!

Goldie has a spacer that makes her take 2 gaskets.

My guess is that it is OE.

 

[Finkaire]

Good news!
Augered out the manifold passages with safety wire and carburetor cleaner, installed a new EGR valve and PASSED!