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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: fuel tuning question
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Tue, 13 September 2005 12:34
 
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| BradW wrote on Tue, 13 September 2005 22:01 |
I don't have any experience with tuning ecu's and I don't know if it would make a difference but do you have a rising rate fuel pressure regulator? An increase in fuel pressure could give the extra fuel.
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Brad, that completely defeats the purpose of having a tunable standalone ECU.
Chris,
for injectors, if they get above maybe 80-90% duty cycle, they may not close properly, giving a higher effective pulse width than commanded.
are you giving 1 or 2 squirts per enging cycle? at 8000 (iirc) 80% duty is 12ms per cycle, but at 6000rpm this is 16ms..
the only other thing i can think of quickly is that you are running out of cams or headflow, such that you still have the boost, but not as much air is getting into the cylinders, and so the result is a rich mixture....
from the commanded pulse widths and AFR's, you could plot the VE (or ar consumed) vs RPM... see if it makes sense..
or combustion is being affected at thoe rpm, resulting in an exhaust mixture that looks rich but possibly isn't?? (clutching at straws here.. ie misfiring etc..)
Cya, Stewart
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