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Rich Idle Holley 4150 #1194581 03/10/12 07:36 PM 03/10/12 07:36 PM
Joined: Jul 2007 Posts: 1,526 North Carolina cjskotni OP pro stock
cjskotni OP pro stock Joined: Jul 2007 Posts: 1,526 North Carolina	Guys, I have been tring to get the demons out of my carburetor (Holley 4150 850 CFM elec choke vac sec) and was still running uber rich at idle. Here's what I have already done: - replaced both power valves and PV gaskets with 65's - replaced needle seat assemblies - set fuel bowl levels to proper level I got to the point today where I turned in the idle mixture screws all the way in (fully lean) and the motor was still running! I then noticed that I had left the choke wire disconnected so the choke was all the way closed. I hooked this back up and turned the idle screws back out a full turn (with motor off). The car seems to idle much cleaner now (no exhaust cloud burning the eyes). The fact that turning the idle mix screws all the way in and not killing the motor usually means a blown PV. However I just replaced these. I am wondering if the choke being closed enabled the engine to keep running and was keeping the mixture rich enough? Is this possible? I have always heard if turning in the mix screws doesn't kill the motor, then you have a bad PV...BUT I JUST REPLACED THEM?? I also noticed the PV's in the carb that I pulled were 35's which I replaced with the 65's in the Renew Kit. The motor pulls about 13-14" of vacuum at 750RPM so I think the new ones are the better choice. What effects would the old 35's have had being so low? This carburetor was sold as "calibrated for a Chevy 502"...I am guessing those motors didn't expect to pull much vacuum.... Any help is appreciated guys! I'd like to think I don't have a PV issue but I am worried the engine being able to run with them leaned in all the way is bad news BUT the choke being closed might mean they could be OK? I am afraid to turn them in again as I don't want the motor to run lean and damage something. Ideas guys?

Re: Rich Idle Holley 4150 [Re: cjskotni] #1194582 03/10/12 08:15 PM 03/10/12 08:15 PM
Joined: Jan 2003 Posts: 5,443 Indiana Y YO7_A66 master
YO7_A66 master Y Joined: Jan 2003 Posts: 5,443 Indiana	A safe torque for Pv's is 100 in/lbs. Did you get them both tight enough? 1970 YO7 A66 [Canadian Export] F8 Challenger 340 (Currently in shop for stroker assy.)

Re: Rich Idle Holley 4150 [Re: cjskotni] #1194583 03/10/12 08:20 PM 03/10/12 08:20 PM
Joined: Nov 2011 Posts: 2,154 Its a TRAP! DARTH V8Я Oh No!! I just had a moron attack!
DARTH V8Я Oh No!! I just had a moron attack! Joined: Nov 2011 Posts: 2,154 Its a TRAP!	Whats the timing set at?

Re: Rich Idle Holley 4150 [Re: YO7_A66] #1194584 03/10/12 08:32 PM 03/10/12 08:32 PM
Joined: Jul 2007 Posts: 1,526 North Carolina cjskotni OP pro stock
cjskotni OP pro stock Joined: Jul 2007 Posts: 1,526 North Carolina	Quote: A safe torque for Pv's is 100 in/lbs. Did you get them both tight enough? I torqued them to that. Seemed to be about as tight (and same orientation) as the old PV's. One funny thing, I noticed the old PV's had two raskets stacked on top of each other where the Renew kit only provided one gasket for each PV and it was a little thicker.... Quote: Whats the timing set at? around 16 degrees advanced base timing - motor is a 499 stroker - OEM electronic ignition with "chrome ECU"

Re: Rich Idle Holley 4150 [Re: cjskotni] #1194585 03/10/12 08:52 PM 03/10/12 08:52 PM
Joined: Nov 2011 Posts: 2,154 Its a TRAP! DARTH V8Я Oh No!! I just had a moron attack!
DARTH V8Я Oh No!! I just had a moron attack! Joined: Nov 2011 Posts: 2,154 Its a TRAP!	Knock a couple degrees out, and see if it cleans up the idle, cause it sounds like all is right with your carb.

Re: Rich Idle Holley 4150 [Re: cjskotni] #1194586 03/10/12 10:52 PM 03/10/12 10:52 PM
Joined: Aug 2003 Posts: 43,163 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,163 Bend,OR USA	Start over from scratch,set both idle mixture screws to 1.5 turns out from lightly bottomed out and start the motor up, let it idle or go drive it so it gets warmed up ot hot, then set the idle mixtures screws(slowly, one at a time) to see if you can make the motor run out of idle fuel by turning the idle mixtures screws in all the way to closed If it still runs then you need to adjust the front and REAR throttle plates so the fronts are adjutsed to be ONLY on the idle circuit, not the transfer or main circuits Let us know what you find out Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: Rich Idle Holley 4150 [Re: Cab_Burge] #1194587 03/10/12 11:13 PM 03/10/12 11:13 PM
Joined: Jul 2007 Posts: 1,526 North Carolina cjskotni OP pro stock
cjskotni OP pro stock Joined: Jul 2007 Posts: 1,526 North Carolina	Quote: Start over from scratch,set both idle mixture screws to 1.5 turns out from lightly bottomed out and start the motor up, let it idle or go drive it so it gets warmed up ot hot, then set the idle mixtures screws(slowly, one at a time) to see if you can make the motor run out of idle fuel by turning the idle mixtures screws in all the way to closed If it still runs then you need to adjust the front and REAR throttle plates so the fronts are adjutsed to be ONLY on the idle circuit, not the transfer or main circuits Let us know what you find out I set the secondary plates to .020" from being fully seated as per Holley recommendations. As far as the primaries go, are you referring to the fast idle screws? I can only think of the fast idle screw and/or curb idle screws being able to adjust the opening of the primaries at idle... If so, don't you set the fast idle screw to give you around 1500 RPMs at engine start? Forgive me here as I am a young guy and still just trying to learn these carburetors. I also noticed the engine wasn't idling down well when you revved it...seemed to hang around 1200-1300RPM in neutral. The only way to get it idle down was to put her in gear and let the tranny stall it down a bit. I did some investigating and it appears the accel pump lever is being contacted too tightly from the throttle lever....preventing the throttle from quite returning to rest when the engine was revved. I have no idea if this would impact the issues I have been having but I will adjust this a bit and see if it helps.

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