SkyWarrior

Ok I have an Lg4 with a 5 speed. All emissions are gone except charcoal canister, and I'm still running a 1984 CCC quadrajet. The TPS voltage is .50 at idle. I rebuilt the quad and have had this problem ever since. When I rebuilt it I used JB weld to plug the casting holes too. But here is my problem, The car has a crappy idle with anything less than seven turns out on the mixture screws, but this gives me a rich condition at idle, so I turned them in a half a turn at a time until the dwell started to vary(and I am using the 6 cylinder scale) I used the IAB to get the dwell to average at 30-40 degrees. The mixture scews were about 5 1\2 turns out at this point, and the IAb was almost all the way unscrewed! The MCS had 4\32 of travel and the lean stop was 1\2 turn from the bottom. The dwell would vary but the car ran like the poop at idle, but was better down the road. (I made all of these adjustments in closed loop I put the mixture screws back to 7 turns out, and moved the IAB down closer to where it should be(using the little guaging tool) and the idle is better but the dwell goes up to the +50* range again. I just want a smooth non-popping idle and to be able to cruise down hills in 5th gear with my foot off the gas and not feel the car hesitate every other second. Please help!

Vader

I've had the same issues in the past. Make sure the O² signal is consistent. Make sure the air bleeds in the primary bores are clean and clear. I've "cheated" this by dropping the float just a bit, thereby causing a slightly leaner mixture all around. The idle mixture screws are probably good where they are, but the lean stop can be raised and the air bleed can be choked back down a bit. The MC will then have a shorter PW to keep the mixture lean enough to satisfy the O².

Good luck. Every adjustment can be a little tricky and critical.

SkyWarrior

thanks for the reply. I replaced my O2 sensor not so long ago but to be honest I highly suspect it to be the cause of my problem. The rebuild sheet that came with the kit said the float level for my '84 carb should be 11/32 but this caused flooding and a rich surge, so I bumped it down to 13/32. Did you mean that my mixture screws should stay at 7 turns? I've heard the newer quads have finer threads but I wasn't sure about an '84. I took the IAB out yesterday and cleaned it. I think I'll do a search and find out how to check my O2 sensor, so I can get that out of the way.