Hello!
I'm new to this forum, also I'm from sweden so pardon my english..

I've got a -85 Caprice wagon (Sorry, know it's a thirdgen board)with 305 engine, and a CC quadrajet carb. I just can't figure out how to make this thing run nice and smooth.

The only way to make the car run decent at cruise and highway speed is to screw the rich stop to the bottom (full rich). Then I can't adjust the IAB. When it run's OK in Cruise speeds, the idle is rough. If I change the IAB to idle smooth the car runs like crap when cruising.
I tried to use a dwell meter to adjust the IAB, but I still can't get it to work both at idle and while driving.

Since the rich stop is all the way in, I get a huge cloud of black smoke in the exhaust at WOT.
Also, after a couple of kílometers on the highway, I get a code 44(lean) Seems kind of weird..

The lean stop is 5 turns out, and the idle mixture screws are 7 turns out. The TPS and o2 sensors are new. (TPS aprox 0.46 at idle) I also replaced the intake manifold gaskets to make sure there wasn't any vacuum leaks there.
Timing is set to 10*btc without the four wire connector to the dist.

Anyone got any ideas of what could be wrong??
I Would be very grateful if someone could help me out.

 

You need to utilize a vacuum gauge to determine proper mixture. If you tightened the rich stop screw all the way.... then of course you're going to run lean, the engine's not getting enough fuel. Tighten BOTH screws all the way, then open them to about 3 1/2 turns EACH. From here.... with the aid of a vacuum gauge, you should start the car, put some bricks behind the tires, put the car in reverse (with you're foot on the brake.... then GENTLY easing off of it). Attatch you're vacuum gauge to a CARB vacuum port (one that reads between 13 - 20.... if none of them do, and they all read lower.... you got a vacuum leak).

When you find one.... adjust the screws until the vacuum gauge can get to it's highest point....

Of course, doing this will affect you're idle speed.... so when you have you're highest reading on the gauge, you can then adjust you're fast idle screw....

Good Luck!

 

I assume you mean that you are trying to adjust the MCS (mixture control solinoid) . You should be able to use a dwell meter on the 6 cylinder scale, and adjust the MCS to read around 30 degrees on the meter (around 50% duty cycle). If for some reason you can't get any readings, there's a problem....

And the black smoke at WOT, is in the secondary circuit, the IAB has nothing to do with that. Try adjusting the AV tension and see if that helps.