Posted By: cjskotni
Rich Idle Holley 4150 - 03/10/12 11:36 PM
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?
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?