Air fuel mixture
-
Skyline_350GT
- Posts: 10
- Joined: Tue Aug 07, 2007 7:23 pm
- Car: 2005 Infinity G35
Air fuel mixture
Hey what's up everyone. I am having trouble with my air fuel misture, well atleast thats what it looks like from my gauge. For a minute it will be running fine and then all of a sudden you see the meter just jump to 17.6-18 any idea what could be causing this?
-
tollboothwilley
- Posts: 3759
- Joined: Sun Aug 26, 2007 7:45 pm
- Car: 2003 G35 Sedan w/ NAV
- Location: LAS VEGAS!!!
- Contact:
Re: Air fuel mixture (Skyline_350GT)
are you boosted? what are you using to control? E-mange, UTEC, Osiris...
17-18 is really lean, you are getting way too much air
where are you thinning out? specific RPM range?
17-18 is really lean, you are getting way too much air
where are you thinning out? specific RPM range?
-
Skyline_350GT
- Posts: 10
- Joined: Tue Aug 07, 2007 7:23 pm
- Car: 2005 Infinity G35
Re: Air fuel mixture (tollboothwilley)
I am runni an APS twin turbo, I dont have an E-manage. as soon as i hit the gas it will lean out! like at 3500 rpm. Now its over heating! I thought it was the radiator cap and chaged that. I need to see if the waterpump is actually circulating the antifreez and if my fan kicks on. If this is all working you have any idea what it cound be?
-
tollboothwilley
- Posts: 3759
- Joined: Sun Aug 26, 2007 7:45 pm
- Car: 2003 G35 Sedan w/ NAV
- Location: LAS VEGAS!!!
- Contact:
Re: Air fuel mixture (Skyline_350GT)
what ECU are you using? how did you have your car tuned??
Overheating in AZ in the winter.... Well, its a good things its not summer yet, or you'd have some serious issues with driving.
I would think that overheating is caused by : a) thermistat b) water pumpc) radiator problemd) head gasket
How much boost are you running? You might be having issues with fuel injectors if you are running lean right when you hit the gas. Does the AFR come back down or is it staying that high?
Overheating in AZ in the winter.... Well, its a good things its not summer yet, or you'd have some serious issues with driving.
I would think that overheating is caused by : a) thermistat b) water pumpc) radiator problemd) head gasket
How much boost are you running? You might be having issues with fuel injectors if you are running lean right when you hit the gas. Does the AFR come back down or is it staying that high?
-
Skyline_350GT
- Posts: 10
- Joined: Tue Aug 07, 2007 7:23 pm
- Car: 2005 Infinity G35
Re: Air fuel mixture (tollboothwilley)
I am using the stock ECU! The car was tuned A long time ago! I would say maybe two years ago!
Yeah I agree that good thing its winter time and not summer. I checked to see if the waterpump was working and correct me if I was wrong in doing this. I turned the car on without the radiator cap to see if I see bubbling to make sure the waterpump is pumping water! I didn't see any water moving or any bubbling. Does that mean the pump is not working? Should I think about changing the thermostat first? and then if the problem isnt fixed the move on to the waterpump? I did check the fans and they are turning on?
I am currently running 9 pounds of boost. The AFR does go back to about 14.7 once the car gets going! It used to go really rich when I would slam on the gas.????????????
Yeah I agree that good thing its winter time and not summer. I checked to see if the waterpump was working and correct me if I was wrong in doing this. I turned the car on without the radiator cap to see if I see bubbling to make sure the waterpump is pumping water! I didn't see any water moving or any bubbling. Does that mean the pump is not working? Should I think about changing the thermostat first? and then if the problem isnt fixed the move on to the waterpump? I did check the fans and they are turning on?
I am currently running 9 pounds of boost. The AFR does go back to about 14.7 once the car gets going! It used to go really rich when I would slam on the gas.????????????
-
Sentientbydesign
- Posts: 5993
- Joined: Wed Feb 02, 2005 8:21 am
- Car: 03 Evo VIII - 330 AWHP
05 Subaru Legacy GT Stg 2 - Sold
05 G35 6MT Coupe - 278 WHP - Sold
04 WW Evo VIII - 302 AWHP - Ex's
96 I30 - Sold - Contact:
Re: Air fuel mixture (Skyline_350GT)
Interesting. My AFRs were really high too on the last dyno. I think I was pushing 16s or 17s centered around 4500 rpm.
It's possible that your lean condition is what is causing the overheating. Usually fuel is used to cool cylinder temps in addition to making the car go "vroom".
If I were you, I'd get another tune.
It's possible that your lean condition is what is causing the overheating. Usually fuel is used to cool cylinder temps in addition to making the car go "vroom".
If I were you, I'd get another tune.
-
awdjdmtalon
- Posts: 624
- Joined: Sun Jun 08, 2008 7:43 am
- Car: 04 G35 Coupe, Diamond Grafite Metalic, Aero package, 6MT
Re: Air fuel mixture (Sentientbydesign)
For the AF issue, I would start with checking for any vacuum leaks, then I would boost leak test the system. If you have either of the two it will cause the AF to lean out.
Pull your spark plugs and see what color the ends are. White to brownish = Lean. Black = Rich.
Next. Is the car over heating under normal driving conditions. (drining around out of boost) If it is, then check the t-stat. Easiest way is to remove it and place it in a pot of water and heat it on the stove, and see if it opens up. If you have a thermometer, but that in there to see at what temp it opens at. If it is opening when it should, then I would suspect a failed water pump or a clogged radiator.
If it is only overheating under boost conditions, that would be from the extreme lean condition you are having. Be very careful. Running that lean WILL blow a head gasket, if it already hasn't. Then that could be the cause of the over heating. I have seen turbo cars that blown HG's and not use coolant or burn it. But will build up excess pressure in the coolant system. And as soon as you relieve the pressure the coolant temp return to normal.
Good luck hope this helped.
Pull your spark plugs and see what color the ends are. White to brownish = Lean. Black = Rich.
Next. Is the car over heating under normal driving conditions. (drining around out of boost) If it is, then check the t-stat. Easiest way is to remove it and place it in a pot of water and heat it on the stove, and see if it opens up. If you have a thermometer, but that in there to see at what temp it opens at. If it is opening when it should, then I would suspect a failed water pump or a clogged radiator.
If it is only overheating under boost conditions, that would be from the extreme lean condition you are having. Be very careful. Running that lean WILL blow a head gasket, if it already hasn't. Then that could be the cause of the over heating. I have seen turbo cars that blown HG's and not use coolant or burn it. But will build up excess pressure in the coolant system. And as soon as you relieve the pressure the coolant temp return to normal.
Good luck hope this helped.