So When i first bought the car it passed with flying colors. This was back when the 350 was running on everything from the 305 that was in there before.

Today i had to smog it again but failed the unburnt HC at idle.

Supposed to be maximum of 120 and considered to be a Gross Pollutor after 270, it measured at 518...

I just made the appointment and went right in no running "Garunteed to Pass" through just went to the station and sat back.


Some things it might be caused by:

--Fuel pressure set to 50 PSI
--Throttle Body Airfoil from TPiS
--I am using the 305 .bin file with the 350 SA tables(with this one i think i will either tweak with the sa tables or just go back the the original AXYC bin and try it out)
--Intake from GT Fiberglass

Before you ask, here is a list of things that i have done to my car.
-Edelbrock intake manifold and runners
-Edelbrock Headers
-BBK AFPR
-Bosch III injectors 22#/hr
-MSD ignition box, coil, plugs, wires, cap, rotor, fuel filter, ignition control module.

Any ideas whatsoever? Any obvious fail culprits?

 

I assume you tested it warm/hot. How old is your cat converter? My 91 has always been unpredictable when it came to smog tests, even in good running order. Any time I failed I replaced my cat each time and passed no problem. I finally made it through 2 checks with 1 cat converter and solid measures (although I have kept the mileage low the last 2 years).

 

If it never went into closed loop, or if it went back into open loop from just sitting there idleing, this would cause the Idle HC's to be a high level no? I lowered the fuel pressure and changed the SA tables back to stock (305 cid AXYC BCC) and the injector flow rate to 19.something and the cyl vol to 713.0cc. I think i will drive it a while and let her warm up real nice and then take another swing at it...