4th gear lean out

K-Series Programmable ECU Calibration updates / downloads
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krystar
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Location: Elgin, IL
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4th gear lean out

Post by krystar » Mon Oct 30, 2006 10:48 am

was datalogging at the track yesterday and was consistently getting lean cut in 4th gear

mods: CTSC 8psi w/ RC 750cc, NGK 2668, CAI, DCRH, DMH cutout after the DCRH flange.

what i don't get is why it's fine in 3rd gear all the way up to 8600 but at 7000 in 4th it leans. I also tried to skip gear and go to 5th gear at 100mph and it also lean cutted me.

The duty cycle looks stuck at 53....it's like the injectors just don't fire any more or something.

Thanks
Krystar
Attachments
byron 2 cutout open.kdl
(372.17 KiB) Downloaded 301 times
byron 13.8 103 cutout closed.kdl
comparison. same calibration, cutout closed
(1.03 MiB) Downloaded 263 times

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Hondata
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Post by Hondata » Mon Oct 30, 2006 11:59 am

What happens when you add fuel at 7500 rpm and above? If the AF does not change, then it is the fuel pump.
Hondata

krystar
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Location: Elgin, IL
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Post by krystar » Mon Oct 30, 2006 12:07 pm

i added like 10% of fuel above 7k and the duty cycle was still stuck at 56. wouldn't duty cycle go up in i increased the fuel table by that much?

i thought fuel pump was only needed at 300+hp..hmm


thanks

Razathorn
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Post by Razathorn » Sat Nov 04, 2006 2:12 am

krystar wrote:i added like 10% of fuel above 7k and the duty cycle was still stuck at 56. wouldn't duty cycle go up in i increased the fuel table by that much?

i thought fuel pump was only needed at 300+hp..hmm


thanks
I think you're a victim of a bad wideband. I've seem this in a datalog before -- after a bit of boost, enough to really heat the sensor up good, and it starts reading dramatically lean. Note that the secondary narrow band o2 sensor doesn't even pick up the fact that you ran lean (not going south of .45 volts) until you've been off the pedal for a while with the injectors cut. That in itself is strange, and in general, the secondary seems to be taking longer to register changes in a/f than I am used to seeing as well -- which makes me wonder if it (and possibly the wideband) has been damaged, perhaps from race gas? It seems pretty strange that the wideband would swing back into the 11s a/f while the TPS was zero. That's another thing that leads me to believe that your sensor(s) are damaged. I'd try another sensor before the fuel pump in my opinion.
2003 black RSX type-s / jrsc @ 12psi / methanol injection / aftercooled

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