n62 maf and fueling problems

[slowpoke2006]

Ok so i hooked up the z32 n62 maf to my rb25det its using the rb20 ecu with latest feature pack. I haven't put my 550cc injectors in yet. I did the maf conversion in nistune cranks and idles great but if i get on it it ran way rich more than my wideband would read.if i adjust my KConst to get fueling good under load my idle afr goes sky high 19-22. should i set my kConst back to close to what nistune set it at and then just adjust my fuel tables to get my under load fueling right. I know i have zero air leaks right now. It did idle a little lean before the change so i plan on replacing my iacv and tps. The tps is because when i tap the gas rpm will drop before it starts to rise. Im still running stock turbo. Just trying to get everything working ok before the new turbo and taking it down to the dyno.

[slowpoke2006]

Ok after re reading the nissan_ecu_tuning_basics.pdf I need to resize maf then resize injectors then adjust my kconst to get my short term close to 0 with no large swings that should get me close to where i need to be. Once that is set then i would need to adjust my fueling map for the high load areas. Just wanting to make sure this sounds right.

[Matt]

Yes that sounds correct in the second post

Basically you want to do the following:

1. MAF resize and then injector resize
2. Get about 14.7:1 (with 0% STFT/LTFT) on light cruise by adjusting K constant/Total injection mutiplier
3. Z32 MAF is rated to 500hp and you may not use the entire load capacity of this MAF necessarily
4. So you may find your trace cursor does not go all the way across the fuel map (say if the vehcile only does 400hp). So you may need to adjust K constant to increase the load indexing on the fuel/timing maps.
5. Offset any fueling adjustments resulting from adjusting K using Total Injection Mutiplier (TIM) to keep 14.7:1 at cruise (say around 2000rpm light load)
6. With larger injectors your mixtures will be richer on boost, so you will need to lower the fuel map so you around 11.5:1 AFR on boost or so

[slowpoke2006]

Sweet thanks that should get it so I can drive it around on the stock turbo,for the next month or so. Then when my new turbo gets here I'll take it to the dyno and let them tune it hoping to be pushing right at 400whp or 300rwkw when every thing is done.

[slowpoke2006]

Got it all worked out i ended up having a bad maf that was maxing out at 5v at 9psi on the stock rb25 turbo didnt notice it till last night that it was doing that after almost zeroing out all my fuel maps. I just reloaded my old base image that i had from before the MAF swap and injector upgrade and re done the maf resize and injector resize and everything came out to be really close to where it needs to be. staying in the - 5 to -8 stft's will get that tweaked out, just got to raise my k constant to get it to go the full map and then drop TIM some more and it should be perfect. Got a new IACV/AAC installed and its idling much better.

[Matt]

Where did you get the MAF from? There are fakes around unfortunately

[slowpoke2006]

I bought it from phase 2 motortrend it was supposed to be a rebuilt n62 maf. I did msged them with the problem and they responded very quickly. In the process of sending it back and getting a refund for it now. It looked just like my used one i got from a junk yard just looked newer/ cleaned up. You wouldn't happen to know what would make timing drop to 7 deg and jump back up at random this is happening while cussing while it is still in the warm up area once it reaches 149f it stops doing it and run with the correct timing all the time. You can see it happen a few times at 3 min mark. then it reaches temp and stops. Not sure what would cause it to do that.

[Matt]

Warmup timing table. Disable this by setting Warmup timing temp range to 0 for min/max

[slowpoke2006]

Well i don't think it matters to much now. Probably fixing to have to pull the motor and rebuild it. Took the car to the drag strip and on my 4th pass i blew the oil sending unit out of the block mid pass. Didn't realize it right away. As soon as i saw i had no oil pressure i killed the motor. Got it fixed and put some oil in it and fired it up after priming the oil pump. It not knocking but when i drained the oil this is what was left in the bottom of my catch pan after poring the oil out. pulled the filter apart and there wasn't really anything in it. Im kinda undecided weather i should go ahead and pull it all a part or wait and see how it does.

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[Matt]

Oh crap...