running lean at 5k rpm and up what to do??? please help out.

[david200095367]

is the z32 TT and NA fuel filter the same? if not, will both fit? probably the TT is most reccomended?

the na and the tt use the same filter steven i checked with nissan. you should change it too. this could be your problem too.

[Craving4Boost]

eeexxcelllennntt.....thanks david

[david200095367]

Ok the car seemed to be fine with the new z32 fuel filter but its back to running lean after 5k rpm. I monitored the injectors duty cycle and it got to 110% at a little over 5k rpm. So does mean im maxing out the injectors and that is my problem?

ps: i have +50 for high map for 5k and up.

[C-Kwik]

also i started my car on a cold start and the idle afr was at 12.3 ish so i minused 9% and it was at 14.7-15 afr at idle. so i drive it for 20 minutes and then i stop at the idle is back at 12.3ish with -9%. So i minus some more fuel and it doesnt do anything. I minus 50% and still nothing. then i add fuel and it gets richer. So at idle it wont get leaner but it will get rich when i mess with the fuel. And if i mess with the fuel before 5k rpm it works, but after 5k it will only richin up from 13ish to 12.3 ish after i add 50% (this is in full throttle). Something is wrong here and i dont know what. Anybody else have any suggestions?

Thanks to all who have contributed so far!

Not that this helps since the pronblem was solved, but you should understand that except at full throttle and shile the engine is stil in cold start mode, it uses the 02 sensor feedback to try and reach the target A/F ratio. So adjustements made in a piggyback are largely useless except at WOT. This is what many experts talk about when they describe the ECU as fighting the piggyback. This is also why a piggyback can be dangerous when running a much larger injector than the ECU is programmed for.

[david200095367]

ok lets put the idle afr problem to the side, but what about running lean after 5k rpm? I added +50% for 5k rpm and up. How can the 370cc be maxed out at only 7-9.4 psi or is that possible?

Thanks c-kwik for the input but do you have any idea about this the above issue?

[NateDogg]

Don't tell me you want your 555cc's back!!

:P

I would get an adjustable fpr and bump the base pressure to about 50psi..or even an FMU or RRFPR with a 4:1 ratio or so. Those cheap ways to get *some* more fuel out of your setup.

[david200095367]

naw it's cool man I dont need the 555cc. Im not aiming for 400hp I just wanted about 250hp and somehow the 370cc are being maxed out.

[NateDogg]

Have you run a 8 gauge wire to your fuel pump through a relay??

[david200095367]

no i havent. what would that help me with?

[Craving4Boost]

nothing for 8psi....