I am in corona and I have tried . . well almost everything to get my truck to pass smog. I have bought a new cat adjusted the ignition timing form 13 advanced to 0 TDC. I have replaced the pcv valve,air filter,the plugs,the wires,distrubtor cap and rotor. I tried additives I replaced the missing resonator and my hc and co are still really high. this may be a stupid question but do I need to change the settings on the carb and how. The smog rep said I was running rich so do I adjust the mixture screw please help and thank you

 

The mixture screw on your carb is sealed, chances are there is something wrong with the carb itself, drilling out the plug involves removing the carb so you mite as well rebuild it, its easy, and only requires hand tools and attention to detail.

 

since you didnt mention the EGR id take it off and make sure its not plugged solid (really common) then there is a plate on the very rear of the head next to the firewall that has a port that feeds the egr, super common for that to be clogged as well.


simple way to test the back plate is to take the egr off and start the motor, should have some flow through the port on the intake side of the head.

 

I found a guy on craigslist selling a rebuilt carb manifold and vaccum lines all setup for 150 i just realized my carb has no wire harness

 

dont throw parts at this.



find out what isnt functioning right, or you'll end up replacing everything to fix one lil problem.



i dont understand how one can rebuild a carb manifold


thats just a intake, its cast, dont wear out.

 

rebuilt carb, < intake manifold and vaccum lines all setup but looks like i dont need it even though i bought it already i popped the plug off the idle mixture screw and screwed it all the way in and than out three times it is much leaner than it was and I am going to try some octane booster and some premium gas we will see how the test goes