Okay I am going to do a major, proper tune up on my car. My question is what order do I do things. For example, do I set the timing first (max advance w/o ping with CCC HEI disconnected) and then make carb adjustments such as idle mixture, idle rpm, fast idle rpm, air bleed, and so on. OR do I do the carb adjustments first and then set timing. Car Craft says timing first, High Performance Pontiac says carb first. I want to know from people who actually own CCC carbed Qjet with Electonic Advance HEI and do their own tuning.
Also on the carb, what is first? Idle mixture, idle speed, air bleed, fast idle speed. All adjustments seem to affect the others, so there must be a proper order.
Thanks.

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1983 T/A LG4 w/T-tops
Rebuilt/Modified E Q-jet
Custom Dual Ram-Air
Self painted cherry red w/ restored black/grey interior
Dynamat from firewall to tail wall
Welded Comp Eng SFC
Tokico Struts/Shocks
Hotchkis LCAs and Panhard Bar
Energy Suspension bushings all around

 

I'd set the timing first (and it's not necessarily max advance w/o ping either.), then set your desired idle speed. Then you set the IAB. The odds of you needing to tinker with the mixture screws is very slim, my 85Z w/ carbed cammed 350 idled just fine w/o messing with them. The IAB is where you focus on these cars.
You set fast idle when you are dialing in your choke, which is a trivial matter in the summer generally. It does not affect any of the other adjustements.
...ed

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Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

 

I agree with Ed, timing first. And while the best value might not necessarily be max advance w/o ping, it sure as hell isn't what the factory called out for on the LG4, which is guaranteed to make the engine run sluggish and use more gas than necessary, especially on the highway. Plus, the odds are very good that the timing mark isn't accurate, they hardly ever are, so trying to hit some number on the mark is pretty useless. Like a carpenter told me once when I tried to apply machine work precision to a piece of wood:

"Measure with a micrometer, mark with chalk, cut with an axe"

The "idle mixture" adjusting screws have almost no authority at all. THey are best left alone at the factory settting, or if they've been disturbed, try 7 turns out. They have a very fine thread.

Idle air bleed is the main thing to control idle mixture. To get a good setting for it, hook a dwell meter to the mixture control solenoid wire that's not pink, which is also the green connector over by the blower motor; on the 6-cyl scale, aim for about 30-40°. This may affect the idle speed hugely, so reset the idle speed to the desired value (700-750 for a stick, 550-600 for auto in gear) and go back to the IAB until you have the correct duty cycle at the correct idle speed.

You may not be able to get the dwell to go anywhere near that high; in that case, you need to epoxy over the plugs in the bottom of the fuel bowl. The vast majority of carbs older than 8 or 10 years have leaks there, which allows gas to be sucked directly into the manifold from the fuel bowl, totally bypassing all metering. This will make the car idle rich, which wil make the ECM think it needs to pull fuel out all the time, so the exhaust will stink at idle but the car will hesitate and bog and will get awful gas mileage.

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"So many Mustangs, so little time..."
ICON Motorsports

[This message has been edited by RB83L69 (edited June 28, 2001).]

 

thanks guys