Air/Fuel question...
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 5,577
Likes: 3
From: Southern Maryland Maryland
Air/Fuel question...
I recently unhooked and removed my oxygen sensors to start fine tuning my combo. Tonight was the first night I have drove the car since I removed the O2s and maybe it was my imagination but it drove better. The car didnt surge @ 1200 like it usually did, idle was better, idle didnt drop at lights. Here's what I observed:
Idle: Air fuel was pretty consistent 14.5-14.7
Cruising 1500-4500: Air Fuel was pretty consistent 13.0-13.5
Going up Hills: Air fuel was pretty consistent 12.6-12.9
WOT: Air Fuel was 13.0:1 across the board.
What can I do to get the air fuel leaner while cruising and going up hills with < 25% throttle?
Phil
Idle: Air fuel was pretty consistent 14.5-14.7
Cruising 1500-4500: Air Fuel was pretty consistent 13.0-13.5
Going up Hills: Air fuel was pretty consistent 12.6-12.9
WOT: Air Fuel was 13.0:1 across the board.
What can I do to get the air fuel leaner while cruising and going up hills with < 25% throttle?
Phil
Drifting
Joined: Apr 2002
Posts: 1,614
Likes: 1
From: DFW TX
Running open loop eliminates lots of the 'jockeying' the PCM is trying to do to hit it's AF and rpm targets at idle and throttle transitions.
For the part throttle cruise, I'm guessing a VE table reduction in those MAP/rpm ranges is the best way to lean out just those areas.
For the part throttle cruise, I'm guessing a VE table reduction in those MAP/rpm ranges is the best way to lean out just those areas.
Safety Car
Joined: Mar 2002
Posts: 4,928
Likes: 1
Cruise-In V Veteran
St. Jude Donor '09
Scan it and see what MAP/kPa and RPM you want to lean out.Then with LS1Edit go to Eng Cal -> Fuel-> Fuel Air Multiplier Table (Open Loop F/A).
Multiplier Table (Open Loop F/A)- These values are the denominator for the for the for the final AFR target.
14.7 (stoichiometric) is the numerator. For instance if the F/A Table value is 1.064 at 55kPa @ 100*C then the PCMs AFR Target is 14.7/1.064 = 13.82.
If you want to further lean it out then change to a lower number..e.g. 14.7/1.032 = 14.24.
If you are running through the MAF you may want to consider calculating a new VE table.
FWIW. Hope this helps some.
Multiplier Table (Open Loop F/A)- These values are the denominator for the for the for the final AFR target.
14.7 (stoichiometric) is the numerator. For instance if the F/A Table value is 1.064 at 55kPa @ 100*C then the PCMs AFR Target is 14.7/1.064 = 13.82.
If you want to further lean it out then change to a lower number..e.g. 14.7/1.032 = 14.24.
If you are running through the MAF you may want to consider calculating a new VE table.
FWIW. Hope this helps some.
