- Jun 26, 2015
- 29
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I'm having idle issues with my 91 notch. Its a stock 91 short block that has a summit dual plane intake, Holley 600cfm 4150 HP, gt40p heads, Anderson n-21 cam, and full MSD ignition. I've researched my problem many times but haven't found anything. I have my timing @14 degrees initial and 23 degrees mechanical all in by 2500rpm. I set the idle mixture screws a turn and a half out like Holley recommends and the car cranks and runs and drives perfect (around my yard) but is very rich with smoke coming from the exhaust. My floats are adjusted properly according to what Holley says and I have 6psi of fuel pressure. So I hook my vacuum gauge up to tune the idle mixture for best vacuum and I can get it to idle fine with 13 inches of vacuum and at 850 to 900 rpm. But when I go to put the car in first or reverse it pretty much dies and runs like crap if I don't give it gas. It doesn't do this when its rich, the rpm barely drops when it's rich. I've sprayed all around the intake manifold and carb flange with carb cleaner looking for vacuum leaks. I can't find any and I only have one vacuum fitting on the manifold and it's for my brakes and it's not leaking. Can anyone please help me diagnose my problem, I keep starting from the top of the list and I always end up back here. Also my pcv system consists of a dash 10 bung welded to my passenger side valve cover with a catch can and a filter/vent on top and the drivers side has just an oil cap, if any of this matters. Thanks for any help Casey.