tune or problem?

[grumpyvette]

Hi there. In New Zealand and have a 72 SS clone. Car was fine for the 1st 3 years after arriving from USA although Cam did mean idle was a little sluggish but no real stall concerns other than when power steering working harder. 6 months ago, started stalling when dropping into drive or reverse and almost impossible when cold.So far replaced 11inch Brake booster (Delco and in case new brake conversion kit booster was faulty), All lines to trans replaced and modulator replaced, trans and gear box serviced with new seals, new stage 1 stall converter installed.Tested for manifold leaks, new header covers, new Quadrajet carby installed, dynatuned and has top of the line Dizzy. Vacuum to booster and PVC valve tested . Car is a rocket when hot and trans shop says car is perfect performance wise. The only thing we could find was a slight flutter in the PCV valve and when blocked off car was a little better. Any help greatly appreciated as out of ideas (and broke)!! Cheers Paul

it always pays to drop back to verify the basics of ignition timing, fuel/air ratio and get out a vacuum gauge, multi meter and timing light,
yeah theres a good many links and sub links but its going to prove rather useful

viewtopic.php?f=55&t=109

viewtopic.php?f=55&t=7763&p=26516&hilit=quadrajet#p26516

viewtopic.php?f=44&t=1142&p=2307&hilit=quadrajet#p2307

viewtopic.php?f=55&t=1144&p=45699&hilit=quadrajet#p45699

viewtopic.php?f=56&t=495

viewtopic.php?f=52&t=181
set the float levels and verify the fuel pressure consistent at about 5 psi entering the carb inlet port
Idle- up too about 2500 rpm try for 14.7:1-15:1 f/a ratio
from about 2500 rpm- too about 4500 rpm try to smoothly and predictably transition the fuel/air ratio mix richer to about 13.5:1
from about 4500 rpm- too about 6500 rpm try to smoothly and predictably transition the fuel/air ratio mix richer to about 12.5:1
this is only a starting point on the tune but it generally gets you in the ball park and tends to reduce the chances of the engine reaching detonation conditions.

set the plug gaps at about .045, make sure the valves are adjusted correctly


related
http://garage.grumpysperformance.com/index.php?threads/carb-tuning-info-and-links.109/

http://garage.grumpysperformance.com/index.php?threads/spark-plug-info.202/

http://garage.grumpysperformance.com/index.php?threads/holley-accelerator-pumps-cams.1790/

http://garage.grumpysperformance.com/index.php?threads/holley-annular-vs-down-leg-boosters.5229/

http://garage.grumpysperformance.com/index.php?threads/holley-carb-power-valves.1639/

http://garage.grumpysperformance.com/index.php?threads/how-do-i-know-the-power-valves-working.11157/

http://garage.grumpysperformance.com/index.php?threads/holley-carb-tune-info.264/

http://garage.grumpysperformance.co...-the-holley-4150-and-4160-series-carbs.10736/

http://garage.grumpysperformance.com/index.php?threads/adjusta-jet-carb-metering-plates.1961/

http://forum.grumpysperformance.com/viewtopic.php?f=55&t=1961

http://garage.grumpysperformance.com/index.php?threads/tune-or-problem.10992/#post-48514

http://garage.grumpysperformance.com/index.php?threads/adjusting-valves.196/


infrared thermometers are a very useful tool to track down issues with tuning, or mal functioning sensors

infrared thermometers are a very useful tool to track down issues with tuning, or mal functioning sensors , without verified facts your guessing.
this is the most consistently accurate I.R temp gun I've used for testing[/img]

http://www.testequipmentdepot.com/e...1100200223789&utm_content=All Extech Products
INFRARED TEMP GUN
Wide temperature range from -58 to 1832°F (-50 to 1000°C)
any time that your dealing with a potential temperature issue or a trouble issue where , knowing the exact temperature vs what a gauge might say, it helps to have a handy and accurate infrared temp gun handy to locate and confirm heat, levels.
viewtopic.php?f=50&t=138&p=168&hilit=infrared#p168
viewtopic.php?f=55&t=109
http://www.harborfreight.com/non-contac ... -8905.html

A quick VALVE ADJUSTMENT IF DONE CORRECTLY HAS THE POTENTIAL TO CLEAR MANY ISSUES RELATED TO IMPROPERLY ADJUSTED VALVES AND WHILE IT MAY NOT BE YOUR ISSUE ITS A FAIRLY COMMON SCREW-UP RELATED TO TUNING ISSUES
A visual inspection tool that easily fits thru a spark plug thread hole is valuable at times

GOOGLE PV-618 and PV-636
READ thru BOTH THESE RELATED THREAD's, ON FINDING TDC and related info

viewtopic.php?f=70&t=1015&p=1864&hilit=tabs#p1864
viewtopic.php?f=52&t=966&p=13811#p13811

TUNING SKILLS MAY BE VERY USEFUL
viewtopic.php?f=55&t=109&p=44341&hilit=+reading+plugs#p44341

viewtopic.php?f=50&t=383&p=470&hilit=vacuum+gauge#p470

a leak down tester is always a good test tool to have access too
viewtopic.php?f=50&t=41&p=49&hilit=+leak+gauge#p49

http://www.harborfreight.com/cpi/ctaf/d ... mber=93547
http://www.secondchancegarage.com/public/186.cfm

BTW remember those cheap crappy fuel filters I told you to never use

well heres where they come in handy, you plug them into the rubber fuel line between the vacuum gauge and the intake plenum where they act like a pulse dampers making the vacuum needle stay a bit more steady and easier to read



A MULTI METER AND TIMING LIGHT WILL BE USEFUL

http://www.harborfreight.com/5-in-1-dig ... 98674.html

http://www.summitracing.com/parts/MSD-8991/