AHHH. You have yourself a Rochester Duel Jet. Thats a two barrel carb. I know nothing on how to tune them like I said. I guess thats not an aftermarket intake after all. Its stock. Maybe not to the car but deff a GM piece. I had one on a 231 that I couldnt get right. I was 17 yrs old then though. My opinion. A 600 Holley on a Edelbrock Performer intake. They can both be had cheap. Ebay, swap meet, or Craigslist would turn up both fairly easy. Good luck. I avoid that set up like the plague. Not that there is anything wrong with it. Just not my cup of tea.

 

Not sure I'd put a 600 carb on a Chevy V6 myself. I'd be more inclined to find a better 2 barrel if I was keeping the V6 for awhile. You can buy adapter plates to go from the Rochester to a Holley 2 barrel, but I'm not positive you'd even need an adapter. They may have the same bolt pattern, so a Holley 500cfm 2300 might bolt right up.

 

Sounds like I should just get a more reliable carb and I'll look into options for that like the holley. Found this on another forum. Gives me a few other things to look into along with the suggestions on here:

RickM
12-04-2006, 12:33:42 PM
Being one of the few who still have the computer hooked up on my 81 I can tell you what is probably going on.

IF you still have all of the computer controlled stuff hooked up the reason your car is running rich is because it is never entering "Closed Loop" mode.

The car will run rich by design when it is in "Open Loop" mode.

Your car is most likely staying in "Open Loop" mode because the Oxygen Sensor is bad/missing etc..

OR

The connection from the Oxygen Sensor to the Computer is bad.

This is the most likely scenario but there could be others such as

Computer not hooked up (maybe unplugged)

Temp sensor (Not the gauge sensor but the sensor the computer uses for temp; you have 2 temp sensors in a comp controlled 81 camaro) is malfunctioning/disconnected.

I suspect your "Check Engine" light is burned out or disconnected; Does is light when you first start the car? (It should light upon start up and then go out. This is a bulb check).

Your Air Pump will not cause the check engine light to come on the car will run fine without it but, it will pollute more.

Your distributor will not have advance weights the timing curve is computer controlled.

If you dont get the computer running you have no hope of passing emissions unless you get a new (Non computer controlled) carb and distributor.

Bottom Line

Check/replace Oxygen sensore; check all connectors; make sure computer is hooked up;

Good Luck
Rick M

 

Geez. The whole time I thought I was looking at a sbc. I had to go back and count the plug wires. I now agree. A Holley 2 barrel is a much better fit. For some reason I thought there were two cars and one had a sbc and the sons had a six. So now I see.

 

Yes just a little 6 cylinder.

The computer issue makes some sense because the prior owner may have made modifications when the motor was rebuilt without accounting for the computer so it could be running in an open loop. So either that or the carb needing rebuilt/replaced are probably the culprits. Thanks again for all of the assistance.

 

There is a noticeable plug on top of computer controlled carbs. Not that they do much. Were talking about '81. Your cell phone has more power than the Apollo rocket did. It basically had some control over timing and fuel mixture. Not sure where it gather information to make changes from though. There werent O2 sensors in cars yet.

To defeat it all you had to do was swap the carb and dizzy. I recently did this on my pickup. The biggest advantage was the amount of vacuum lines. The factory ran EVERYTHING on vacuum in those days.