Hi all. If anyone is a super genius with CCC carbs..... I have an issue. Had my carb rebuilt by a very reputable old school outfit and it seems to work great but it stalls at idle. If I flick on the ac...causing the idle to increase a few hundred Rpm it's fine. Which is to say 700 curb leads to surge surge stall......but 1100 rpm idle is fine.....other than the obvious pulling. OBD1 is all in tact and in play. BPS, O2, TPS, etc all checked and within spec....so I am told. Vacuum gauge is steady as a rock. No bad vac hoses or carb gaskets as far as I can see. Any thoughts?
CCC carb idle issue
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What is the air fuel mixture dwell at idle? You need at least a old analog dwell meter to figure out CCC issues.
Sounds like the carburetor may be set up ok otherwise, but your idle circuit is going to need help. I'm no CCC carb expert as there's probably only a handful left in the country, but I stayed at a Holiday Inn last night. 
Don't go by the inside tach for your idle speed setting. For an 86 442, timing is 20 degrees at 1100 rpm in park. 650 in Drive, and 750 on low step of fast idle cam. That's per factory specs. If your tach in the car is reading a bit high, you could actually be lowering your idle speed TOO low if you only go by the factory tach. Get a tachometer that is more accurate.
Is it starving for fuel or starving for air? That's the first thing you need to do is figure that out. Rock-steady vacuum doesn't mean much if it's rock-steady low. A dwell meter can help you figure out what it's doing. Of course it should be in open loop during idle. Meaning the O2 sensor is <600 degrees. After the engine is warmed up to operating temps, and at idle, you should see a fixed dwell as the ECM doesn't take into account your "cold" O2 sensor input. You should be roughly 30 degrees fixed on the 6 cyl scale regardless of what engine is in the car. To test to see if it's really fixed, open up a vacuum leak by pulling a vacuum hose off and see if dwell changes. It shouldn't.
If everything seems to be great off-idle, then you may need fuel/air adjustments at idle and transmission in drive. Mixture screws in the front (the ones that the covers have to be dug out) don't do a whole heckuva lot but making sure they're balanced side to side it kinda important. If everything else is great, then turning those screws in a little at a time SHOULD change your dwell. If it does, great, you are looking for the highest idle attainable with the mixture screws as well as being around 30 degrees dwell. If I were going to guess, it sounds like you may not be getting enough fuel at idle. The IAB (idle air bleed) adjustments could be whacked as well. I'm just wondering if they set up the rich and lean stops properly as well? Sounds like they may have if it runs well off idle. J-33815-2 is the IAB setting tool. You want to set the IAB valve to just touching the bottom of the gage. That is, if you have a letter on your IAB. Don't monkey with it if you're not sure what you're doing with it. Once you get one thing out of whack, it can wreak havoc on overall driveability.
Will it idle long enough as to cup your hand over the primary air horn or manually close the choke plate some? If your idle smooths out doing this, then it's a lean condition.
My suggestion is to contact the folks that rebuilt your carb and ask them if they can remember what they did and ask for their suggestions. If they didn't clean a passage properly or set the IAB or other adjustment properly, you could have idle issues.
Don't go by the inside tach for your idle speed setting. For an 86 442, timing is 20 degrees at 1100 rpm in park. 650 in Drive, and 750 on low step of fast idle cam. That's per factory specs. If your tach in the car is reading a bit high, you could actually be lowering your idle speed TOO low if you only go by the factory tach. Get a tachometer that is more accurate.
Is it starving for fuel or starving for air? That's the first thing you need to do is figure that out. Rock-steady vacuum doesn't mean much if it's rock-steady low. A dwell meter can help you figure out what it's doing. Of course it should be in open loop during idle. Meaning the O2 sensor is <600 degrees. After the engine is warmed up to operating temps, and at idle, you should see a fixed dwell as the ECM doesn't take into account your "cold" O2 sensor input. You should be roughly 30 degrees fixed on the 6 cyl scale regardless of what engine is in the car. To test to see if it's really fixed, open up a vacuum leak by pulling a vacuum hose off and see if dwell changes. It shouldn't.
If everything seems to be great off-idle, then you may need fuel/air adjustments at idle and transmission in drive. Mixture screws in the front (the ones that the covers have to be dug out) don't do a whole heckuva lot but making sure they're balanced side to side it kinda important. If everything else is great, then turning those screws in a little at a time SHOULD change your dwell. If it does, great, you are looking for the highest idle attainable with the mixture screws as well as being around 30 degrees dwell. If I were going to guess, it sounds like you may not be getting enough fuel at idle. The IAB (idle air bleed) adjustments could be whacked as well. I'm just wondering if they set up the rich and lean stops properly as well? Sounds like they may have if it runs well off idle. J-33815-2 is the IAB setting tool. You want to set the IAB valve to just touching the bottom of the gage. That is, if you have a letter on your IAB. Don't monkey with it if you're not sure what you're doing with it. Once you get one thing out of whack, it can wreak havoc on overall driveability.
Will it idle long enough as to cup your hand over the primary air horn or manually close the choke plate some? If your idle smooths out doing this, then it's a lean condition.
My suggestion is to contact the folks that rebuilt your carb and ask them if they can remember what they did and ask for their suggestions. If they didn't clean a passage properly or set the IAB or other adjustment properly, you could have idle issues.
As said, verify your actual idle speed. I personally like around 1000 in park and more like 850 in gear. Checking the mixture solenoid function and setting is also a good idea. Spray around carb cleaner for a vacuum leak and double check vacuum hose shape and positive connection.
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