Tune Jumping?
02-27-2009, 09:28 AM
#1
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Location: Snowshoe, WV, Centreville, VA
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Tune Jumping?
I'll jump right into my issue. I have the Apex'i NEO tuning my DE-K Swap with stock 99 ecu and harness. I usually run 10-15 points lean from 1000-6000 rpms at 12.5-13 a/f ratio (above 50% throttle). Every once in a while my tune will jump and Ill be running 16-18 a/f ratio above and below 50% throttle. I thought this might be my exhaust leak causing this, but I've replaced all gaskets. When it jumps its always consistent in how much it jumps, so i have tune settings on a piece of paper to tune from lean to rich and back.
No codes.
Any help?
No codes.
Any help?
03-05-2009, 12:28 PM
#7
To the OP, have you checked your fuel injectors or fuel pump.. Maybe you have an intermittent problem with an injector/injectors or pump where the injector cuts out or the injectors are partially blocked and is leaning out the mixture or the pump is on its way out and you have intermittent fuel pressure drop.
Also check to see that MAF voltage rises in a linear fashion as RPM rises and check your TPS for proper calibration and that voltage rises without dips and is also linear according to the throttle position. This most likely isnt your issue but never hurts to check the simple stuff first.
Last edited by whlimi; 03-05-2009 at 12:37 PM.
03-05-2009, 03:46 PM
#9
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Join Date: May 2005
Location: Snowshoe, WV, Centreville, VA
Posts: 6,180
If AFR is tuned according to MAF voltage, then the cold air wont affect the tune because the MAF will compensate for the denser air. But if your tune is based on throttle position, then ya it will change with temperature.
To the OP, have you checked your fuel injectors or fuel pump.. Maybe you have an intermittent problem with an injector/injectors or pump where the injector cuts out or the injectors are partially blocked and is leaning out the mixture or the pump is on its way out and you have intermittent fuel pressure drop.
Also check to see that MAF voltage rises in a linear fashion as RPM rises and check your TPS for proper calibration and that voltage rises without dips and is also linear according to the throttle position. This most likely isnt your issue but never hurts to check the simple stuff first.
To the OP, have you checked your fuel injectors or fuel pump.. Maybe you have an intermittent problem with an injector/injectors or pump where the injector cuts out or the injectors are partially blocked and is leaning out the mixture or the pump is on its way out and you have intermittent fuel pressure drop.
Also check to see that MAF voltage rises in a linear fashion as RPM rises and check your TPS for proper calibration and that voltage rises without dips and is also linear according to the throttle position. This most likely isnt your issue but never hurts to check the simple stuff first.
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