I have a '84 Bronco II 2.8 v6 automatic. I rebuilt the motor about twelve years ago as well as the trani and t case. It ran fine and passed emissions test that we have in Colorado for two years an then suddenly it would not pass and I've had it parked since then. I got it up and running and got a new carb for it and it runs great except for a little loss of power and it gets about 12 miles per gallon. Now for the question. Does any one know where I can find a good bypass valve for the A.I.R. system. I can get one from Rock Auto at about 250.00 bucks but it isn't the same as mine. Theirs has a flange mount and a hose connection as well as 2 vacuum lines. Mine has two hose connections and 1 vacuum line. I have found the diverter valve and it is on its way. Neither of these two parts will hold vacuum so I'm hoping this is the problem with the emissions as well as the fuel consumption. Any help with this subject would be greatly appreciated as this is going to be a complete restoration.

 

So it failed a 5 gas analyzer I/M inspection? what part of the test was failing? MC? provide the spec limit and measured data.