carb issues
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On The Tree
Joined: Aug 2015
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carb issues Motor is a 04 5.3 stock bottom end with a tsp cam 228/232 .600/.600 and correct springs. Holley single plane intake, proform 750 carb. 4.5 powervalve 71/81 jets. Long tube heades. Timing is set at 10* 0rpm, 19* 800rpm, 29* 2000rpm on. car was eunning decent, a little rich but still drivable yesterday it started running so rich(atleast i think), that it dumps smoke out of the garage and burns my eyes so bad I can't stand in the garage for more than 30 seconds of the car running.
I know the power valve is not blown (checked it)
I cleaned the carb so I know it's not dirty.
Idle transfer slot is adjusted properly
Idles at 1000rpm
Idle air screws are all set at 1.5 turns out.
Any ideas?
I know the power valve is not blown (checked it)
I cleaned the carb so I know it's not dirty.
Idle transfer slot is adjusted properly
Idles at 1000rpm
Idle air screws are all set at 1.5 turns out.
Any ideas?
10 Second Club
Joined: Aug 2010
Posts: 4,465
Likes: 192
From: Harford Co. Maryland
IAB's are not always at 1.5 turns....just a starting point. (mine are 1/2-3/4 turn out)
What is the fuel pressure ?
Is there fuel coming out of the bowl vent ? (stuck needle/seat...dirt)
What is the fuel pressure ?
Is there fuel coming out of the bowl vent ? (stuck needle/seat...dirt)
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Verdad Gallardo 10 Second Club
Joined: Aug 2010
Posts: 4,465
Likes: 192
From: Harford Co. Maryland
Idle screw out (lower rpm) close the butterflies some was where I was going.
All adjustments should be done on a fully warmed motor also. (at operating temps)
Double check your timing also.
All adjustments should be done on a fully warmed motor also. (at operating temps)
Double check your timing also.
You can back off your timing to adjust idle speed. The MSD box lets you put in a super low value at 500 RPM. That should allow you to keep the transition slot where it needs to be but keep idle down. Put the 1000 RPM up where you want it, that way you get good advance as soon as you are off idle.
If no leaks and float level is right than you just have some tuning to do. Like said above you might need to put the idle mixture screws at 1/4 turn. At that far in you will probably want to adjust your idle air bleeds and maybe idle feed restrictor to get some proper adjustment.
Mine are around 1/2 turn. I keep thinking I should tweak it more but car is running well so I am happy.
Another option might be a bigger cam, LOL. Stock cams on LS motors seem to have a lot more low end carb draw than the old first gen motors. This is a common tuning problem on these motors.
If no leaks and float level is right than you just have some tuning to do. Like said above you might need to put the idle mixture screws at 1/4 turn. At that far in you will probably want to adjust your idle air bleeds and maybe idle feed restrictor to get some proper adjustment.
Mine are around 1/2 turn. I keep thinking I should tweak it more but car is running well so I am happy.
Another option might be a bigger cam, LOL. Stock cams on LS motors seem to have a lot more low end carb draw than the old first gen motors. This is a common tuning problem on these motors.