high load high rpm WOT too rich

Discussions concerning the M7790 cpu

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lynchfourtwenty
 

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Joined: Sun Feb 14, 2010 10:02 am

Re: high load high rpm WOT too rich

Post by lynchfourtwenty »

just went for a test drive with the new bin, cold idle is fine, warm idle is lean for a few seconds then settles right on 14.7, a quick blip of the throttle shows 13 afr's then as the rpms settle it goes 11,12,13,14.7.

cruise afrs are high 15's to mid 16's above 3000 rpm, 2500-3000 is 14.7-15.0. zero psi = mid 16 afr's, i didnt go past that.

after doing some researching it seems like my maf is showing too much voltage in the higher rpm area, 4.4v, from what i've gathered that should be over 300hp, when i cross reference my injector duty cycle 79% so .79x520 thats in the 250hp range which is about what virtual dynos showing me.

so i think we're on to something here, im going to try to have my friend solder the wires for me an keep as much of the factory shielding as possible.
Matt
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Re: high load high rpm WOT too rich

Post by Matt »

Just checking, when you switch to N60 MAF (J30 Maxima 1990-1992) you are switching VQ maps to that model yes?

N62 (Z32 MAF) uses the Z32 VQ map as you had in the tune

Mismatched VQ maps will show lean in some spots and richer in others due to incorrect calibration. Shielded wires are single insulated wire surrounded by more multistrand wire which goes to ground (ie to shield the inner signal from noise)
lynchfourtwenty
 

Posts: 108
Joined: Sun Feb 14, 2010 10:02 am

Re: high load high rpm WOT too rich

Post by lynchfourtwenty »

actually, i found that the ECR33 RB25DET was the correct vq map to use, but yes the maxima is where i got the maf from, not sure if the vq map has changed for the maxima in nistune recently but in the past i found it wasn't right.

the only thing that changed when going blow through initially was maf placement, and i started with the n60, but i had a n62 that i had been planning to install, and since i was having issues i figured why not, but its having the same problems as the n60 was.. once i put the n62 in i changed to the n62 vq map.

i always use nistunes auto maf change feature.
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