Smog pump/diverter valve delete

[Cbitz233]

I have a the 305 in my 83 Avanti. Has anyone gotten rid of the smog pump equipment? If so, how did you do it and any tips. Thanks

[Avanti83]

If you are serious, you will need to replace the carb, dissy and coil. The 83 has an interesting emissions system in that it is a separate system that controls the carb and spark through the ECM. Everything else on the engine is there to provide info to the ECM. The OEM carb is a goofy unit that has an electric controlled jet setup, way outdated now. By replacing the carb with a 550CFM or so unit and a standalone vacuum advance dissy and coil you render the rest of the emissions system redundant.  The engine is now back to the way it was in the 60's and 70's. You can strip off all the emissions crap and plug the necessary ports. A cam change will provide better performance but the 83 should run just fine in this configuration.

When I dropped the 355 roller SBC into my 83, I was amazed to find the ECM setup and wiring was an add-on to the stock earlier wiring system and I stripped it out leaving the older wiring intact.

Your money, your choice as a member is fond of saying. I actually used a Holley EFI setup on the 355 engine but a good carb and correct Dissy will suffice for street use. The carb and dissy setup are what I have on my 74 383 SBC setup.

[Cbitz233]

I have a Edelbrock 1406 or 05 on it right now. Do I need to get a delete pulley to delete the smog pump. Never done anything emissions related so I'm hesitant.

[Avanti83]

16 hours ago, Cbitz233 said:

I have a Edelbrock 1406 or 05 on it right now. Do I need to get a delete pulley to delete the smog pump. Never done anything emissions related so I'm hesitant.

I can understand your hesitation if you have never done it before. If the car drives well currently you may be able to just put a smaller belt on the system and bypass the smog pump. It's been so long since I've had one on an engine I can't picture your setup in my memory. You only need a delete pulley if the belt rubs somewhere when you bypass the pump. I think the delete is required when you remove the A/C compressor IIRC. 

Try that before you go any further. I don't want to see you get part way into a conversion and have trouble because if you start pulling parts you will have to plug holes and add cover plates to an already good running car.

 

Edited September 12, 2018 by Avanti83

[wwundt]

RQB3430 1982 Avanti-II.   I installed an Edelbrock 1403 500 cfm carb and Edelbrock Performer Model 2701EPS intake manifold, HEI distributor, and removed the smog pump equipment. The old GM air cleaner will not fit the Edelbrock carb. The new Edelbrock air cleaner required a 3/4 inch lower air cleaner element in order for the hood to close.  I also installed a 4th gear kickdown switch to overdrive, necessitated by the removal of the old computer-controlled carb and distributor.  Without the computer, the transmission could not otherwise shift into overdrive.  

 

[wwundt]

[NHcamper]

Be carful with the hood clearance. My car has aftermarket air cleaner on it and P/O cracked the hood. I assume the air cleaner wing nut did it. 

[Paul K.]

All due respect to posters here but I'm curious how just removing the smog pump on an 83 requires replacing the carb and distributor? The air injection system (air pump) is post- combustion. In simple terms it "stokes the fire" by pumping O2 into the exhaust manifold or catalytic converter to reduce Hydrocarbons (HC) and Carbon Monoxide (CO) that hasn't completely burned. After engine warm-up, it pumps O2 to the catalytic converter making it operate its best and further reduce the HC and CO. This is downstream of the O2 sensor so the exhaust read by the O2 sensor is not treated with O2 from the air pump. (that would cause an artificially lean condition making the computer richen the mix unnecessarily)  All of this activity happens AFTER the fuel and ignition systems have done their jobs.

I would just remove the air pump and related plumbing. You will need to plug the air injection ports on the cylinder heads with scew in plugs. Short bolts work but hex head cap bolts look better. I would also remove the catalytic converter. with the air pump removed the exhaust will be less reduced forcing you to run the engine more lean to avoid the "rotten egg" smell from the exhaust and potentially melting down the converter. Pretty sure there was a vacuum hose from the coolant temperature sensor to the air pump diverter valve which will have to be plugged too. If there is a computer controlled solenoid for diverter valve, it can be bypassed to "trick" the computer into thinking it is working preventing the check engine  or service engine engine soon light form coming on.    Disclaimer: Check with local and state laws to find out if removal of emission controls is legal..    

Edited October 21, 2018 by Paul K.

[arkus]

i've been wrong many times but i think messing with emission controls, especially cats would violate federal laws and subject one to some pretty serious fines. i was a licensed inspection mechanic for 46 years and no way would i allow this sort of "repair" in my shop. just my tcw.

[Paul K.]

Arkus you are exactly right, hence my disclaimer.

Here in CA, vehicles require a smog check every 2 years for model year 1976 and newer. HOWEVER, it is illegal to remove emission control that were originally installed on any vehicle.  Emission controls began in early 60s with closed PCV systems, then air injection in 66/67, evaporative canisters in 71, EGR in 73 and catalytic converters in 75. My point is just about any pre-76 old car we see at car shows has had these items ripped off and these people could be cited if inspected by a Bureau of Automotive Repair inspector. But the cars are too old for a biennial smog test so everyone thinks its legal. 

If the OP doesn't need a routine smog test he won't have any issues unless knowing he is polluting more bothers him   Also, when he goes to sell the car it would be a problem to sell to a person from another state like CA that requires emission controls to be intact and operational.  

[Skip Lackie]

Agree with arkus and Paul K.  Removing or disabling any originally-required emissions equipment is a violation of Federal law.  However, the Feds don't have any auto emissions cops, so enforcement is left up to the states.  That said, in most states, vehicles with antique/historic plates are exempt from emissions inspection.  In others, vehicles older than a certain year are also exempt, even if they have regular plates -- so there's no enforcement mechanism in either case.  Add on to that the fact that some components of early emissions-control systems are no longer available and you have a situation in which it makes sense to remove some of that ugly stuff, especially if it's no longer working right anyway.  But don't throw it away and be aware you may have to 'fess up if you sell your car later.