when i start my car cold my a/f's read 13.5-13.7. once the motor gets hot the gauge starts to jump from 14.0-16.1 back and fourth. this is on a ls motor using an aem uego gauge.
any ideas or input would be appreciated.

 

What fuel management system are you using ?

 

im runing a stock ecu with fmu and inline pump. i know that the fmu sucks and i should ditch it. the a/f's were fine before. im just trying to get the little bugs worked out before i get it tuned.

 

Is this really a bug tho? Does it affect the idle? Thats not real lean for idle actually. I idle at 15.5 all day long.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Is this really a bug tho? Does it affect the idle? Thats not real lean for idle actually. I idle at 15.5 all day long.</TD></TR></TABLE>

Every car is different but you are right. Most cars idle fine from 14:1 - 15.5:1. The only problem I see is it's fluctuating two full points at idle.

 

I guess it depends on how fast its fluxuating. Is it over time as its warming up or back and forth every second or so? Could be caused by a misfire.

 

once its hot it fluctuates every second or so.

 

it does affect the idle.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WEST*SIDE &raquo;</TD></TR><TR><TD CLASS="quote">when i start my car cold my a/f's read 13.5-13.7. once the motor gets hot the gauge starts to jump from 14.0-16.1 back and fourth. this is on a ls motor using an aem uego gauge.
any ideas or input would be appreciated.</TD></TR></TABLE>
That's all normal operation.

 

is this normal whils driving? once i hit boost it runs richer.

 

every car will idle different injector size will play a part in this. i run 1000cc's my car not happy at idle unless its like 12.3:1 or so. a/f at idle really does matter there is no load on the motor