EGR passage cleaning via removal of intake manifold?

1982 2.6 L ,190,00 miles, California dual EGR valve is super clean now. Carb removed. But where are the passages thru the cylinder head to the exhaust valve ? It is DEJA VU , as I did this job about 15 years ago, without removing the intake manifold. Cannot recall technique, but I think I used gun cleaning brushes and sprayed Berryman solvent into the passages somehow. It was messy and time-consuming. Will use a small inspection mirror thru top of intake manifold tomorrow, to find the passages.??

Bought a Harbor Freight engine brush kit, and have charged up my drill.

Choke problems plus personal problems neglected maintenance of this type for years, but passed smog until recently. New catalytic converter via California Consumer Assistance Program about 5000 or fewer miles ago. Did I wreck it by running obviously rich starts too long? Cats available in Tijuana , such as at King Muffler, but are they good performers? Calif. CAP program is one time only per vehicle/ owner of that vehicle.

Was 50% high on CO in October, so failed the test. Recent free tests at a non-STAR good old boy shop indicates high NOx now, with little CO. This after I activated the high altitude compensator HAC ( I am near sea level) on the wheel well to inject more air, per the expert good-old-boy who says that " Honda did it this way also".

Should the sub-EGR valve setting screw be adjusted such that the sub-EGR is completely closed when the (primary) throttle is closed?. Or, should it be partially open then? Haynes book and figure say it is factory set, so do not move. But somehow, mine makes valve completely closed when throttle is closed. But that spring vibrated? loose, beyond the reach of the compression spring, and seems ready to maybe fallout. Maybe has been that way since a carburetor cleaning for a really low price, abut 8 years ago at Carburadores Rodriguez in Tijuana ( where there are yet may carbureted cars, such as old taxis).

There is a single exhaust recirculation gallery that runs from a small port inside exhaust port #4 through the head to just below #3 inlet port. It is a dead straight line between these 2 ports - in the past I've used a drill bit to clear the gallery out when it had gotten completely blocked with carbon. If it's not that bad you could get away with using those small tube brushes. If the recirculation gallery through the head is coked up you can guarantee the rest of the gallery through the inlet manifold will be blocked to some degree too. This is one of those jobs where removal of both manifolds would ensure you'll be able to give it a thorough clean. I'm not familiar with the anti-smog gear fitted for Cali regs so I can't offer any other recommendations.

In my last paragraph, in the first post, above: "But that spring vibrated (?) loose......." should be "But that SCREW vibrated(?) loose.....

Thank you, geezer 101. I replaced a cracked exhaust manifold perhaps 7000 miles ago, including retap upsize in the head at position next to the firewall where a subcontractor presumably stripped the thread when reinstalling my original exhaust manifold after head gasket replacement and light head milling at a widely used engine rebuild shop , Franco, in the auto repair district in eastern Ensenada , Baja California, Mexico, about 80 miles south of the border.

I now recall the EGR gallery opening visible from the exhaust manifold side, when I personally replaced the cracked original exhaust manifold .
Obviously , I hope to work from the intake side only,
preferably without intake manifold removal. I recall some cleaning from exhaust side during exhaust manif replacement. "Coked up" now does not seem likely , because at least two smog 2-year inspections have passed since then for NOx, and few miles, albeit with very rich starts and probably one or two cylinders reluctant to fire for a few seconds after start, have been driven Have changed oil, air filter, spark plugs,( obviously too rich indicated) since failing on CO last October and minimal driving on paid registration but no current license tag until it passes smog inspection. It ran fine last week , with low CO but high NOx , on one-day permit, before I removed carb. and cleaned and checked function of the California dual EGR valve and the sub-EGR valve.

? Brushes from intake side to start, with(?) Seafoam or other then(??)oven cleaner, followed by water plus light oil product mixture rinse, followed by Seafoam(?), Lucas light oil (?), or is this fantasy?

Is there a way to edit after posting ? Typos occur, and new results / rethinking.

By the way, the mentioned last week cleaning of Dual EGR and sub-EGR was not big. I did a more extensive, unpleasant , first time for me cleanout there at least a decade ago, while parked in a public parking lot near an auto parts store, sleeping inside the camper shell, not wishing to antagonize family members and neighbors with smelly high strength carb cleaners ( maybe not now available , ff. Calif. environmental regulations?).

To be honest I doubt spraying anything through the EGR galleries will clean it out. More than likely it will gum it up even more. When contaminated carbon build up starts to dissolve, it makes one hell of a mess. I think this is one of those jobs there just aren't any 'easy ways' or short cuts.

Quote:

Originally Posted by gordiray

Is there a way to edit after posting ? Typos occur, and new results / rethinking.

Edit functions are one of the benefits of becoming a donator. Otherwise, I think just being a member excludes edit privelages.

Now have 3 foot long lengths of several diameters of wire cable , to about 3/8 inch. Propose to put into drill chuck, fray the opposite end of the cable, and pass through the EGR gas source, ( the lower hole on the intake manifold), as a 'Roto-Rooter', either dry or with some solvent for carbon.

Would plunge the cable in and out , as the drill motor spins it at low speed.

When it bottoms out somewhere on the exhaust manifold, or someplace in the cylinder head at or near the EGR source, would this damage an exhaust valve ( which might or might not be open then)?

Perhaps , after feeding some length of wire ( how much?) in with the drill motor, one should stop the drill and turn and push the wire in and
out via a hand chuck or gloves.

Now recall use of a discarded speedometer cable a few years ago. Do not recall if I used a drill motor.