another year another emissions test

Yes, my '76 without cats passed once again in NV. 88 hydrocarbons at idle and 91 at 2500rpm. I hate the procedure of it all but it gives me piece of mind that I have the ability to make this thing pass when I want to. This is nothing that a bit of tinkering can't accomplish with a healthy engine.

 

I no longer have the thermal reactor muffler, but rather a high flow Ansa sport muffler. I hook up both air pumps, make sure idle jets are stock .55 ran with about 4 turns out as opposed to 5 where it runs best, mains are stock 135 with 220 air correctors, and I retard the timing so it is sitting about 2 advance and adjust the throttle plate accordingly so it will idle. Once done, the engine needs to be warmed up and then ran *hot* to the point were the pipe tips are showing some white inside. This way you know it is lean and the air pumps are doing their job correctly. The car will run poorly but no worries just make sure you do not have a lean misfire. It does not take very long with this arrangement due to how hot the engine runs with the timing and air pumps set up like this. Installing new plugs and changing any dirty oil helps as well. Passing even California emissions is not a problem with a healthy engine. California allots I believe 220 hydrocarbons at both 1000rpm and 2500rpm for a '76. I yielded less than 100 hyrocarbons at 2300 feet elevation, no humidity (desert!), and 95 degree weather. You should be ok.

 

Ya know I thought I could do the same thing. I hooked up the air pumps and did nothing else and it was not even close to passing. I was running about 10-11 degrees timing at idle. My guess is the thermo is not going to be able to burn off the rest but let us know how you fare regardless