this is re: my 77 20r -- i'm replacing the stock carb with a weber 32/36, but every tutorial/video i find does not address what to do with the air injection pump -- can i just leave it in place? -- or will that have an effect on performance? -- its not like the 22r that i could remove the rail and block off with plates, the 20r has a different exhaust manifold which incorporates the rail tubing in the manifold

 

I have an '80 (20r) so can't be sure. I did a total 100% de-smog and it now runs fantastic. See where the hoses go, you may have to buy or fabricate a block-off plate. Try LCEperformance.com . I'm sure any smog equipment it had on has quit working decades ago.

edit. I completely removed the air pump including brackets, much cleaner engine bay now.

 

Agree with "nor al 67". Removal of the smog junk and adding the Weber and a header and a 2 1/4" exhaust resulted in an great running engine now. You CAN leave the smog pump, but you'll get rid of about 30-40 pounds of excess weight and a lot of junk if you remove it. My smog pump hardware was leaking exhaust gas too--at the exhaust manifold. I no longer smell exhaust gas when driving. I also doubt whether any of the smog junk was still working as it was designed to do. Hopefully you live where smog inspections are not mandatory/required.

If you haven't done so, you MUST read the 22R de-smogging thread(s) here on YotaTech. Absolutely a must! I read the entire thread 2-3 times before I started the conversion on my '83--it helped immensely! See the "sticky" above.

 

thanks, guys -- yeah, i've read the stickies, very helpful, but a few things that don't apply to the 20r, like the different exhaust manifold -- i did find from another forum that on the 20r, the air injection rail can be left in place, even if i remove the smog pump, since there is a one-way valve to prevent any exhaust leak -- i need to leave the pump in place, however, since it acts as the tensioner for my a/c, but i will be disconnecting it from the air injection rail -- and the air injection rail needs to stay in place, since the block-off plates that came in the kit are for a 22r, and so removing the rail would create mega exhaust leak!

 

I read a thread--maybe on here--about a guy who gutted his smog pump, effectively converting it into mothing but a tension pulley for his AC. Maybe you could search for that, as it sounds like a potential solution for you. he used some plastic plugs to fill in the holes at the back of the pump that were left after he gutted it.

As far as the holes that remain in the top of the exhaust manifold, I found some bolts in my stash that almost fit in the holes, but were just a skosh too loose. So I bought some high-temp exhaust patch/goop from Auto Zone, and just glued the bolts in place in the holes. Then painted it all with high-temp black paint from Wally. Worked fine and lasted several months until I installed the header. You can barely see the front bolt, under the shadow of the #1 plug wire in this photo:

 

yeah, i came across one guy who gutted it, and another guy who fabricated a tensioner for the a/c, but for now, i'm feeling lazy

also came across a guy who did like you did, but tapped the holes for the bolts -- but if i can just leave the rail on, even though its not a clean install, no biggie