VERY Strange issue .. Definitely need some input! Lean condition @ WOT

[nelsonmxmarc]

Wideband is reading 'okay' because both the innovate and AEM are reading identical values.. I know the theoretical values in Nistune are more approximation than anything until the PW is accounted for/adjusted.

At any rate, it seems the MAF scaling for my z32 MAF was off. The K value was not accounted for and the scaling was off.. So basically the voltage was "high" fooling the ECU into thinking it was running lean. 1.55v at idle vs. 1.2v with N60 MAF (Basically like stock rb20).

Since the thermister readings we're HOT, it assumed lesser air flow, leading to less fuel = lean.

I'll need to try another Z32 maf before returning to the dyno to make sure its not the maf at fault, but as far as i can tell, the scaling and loads are all off for the MAF / AFR.. Also, when i entered the K constant for the Z32 MAF, the car died almost instantly. This also led me to believe the scaling was all off, otherwise the change of maf in nistune wouldn't have resulted in this.

I'm now back to square one - Previous tune and N60 maf - No lean condition, but very rich as in 12:1/11:1.

I may toss the new map back in, since this N60 maf works well with it (also pointing to why the z32 was no properly installed) and then adjust the AFR's respectively..

I started off by overwriting knock maps. Since my knock sensors are ka-put, i figured this would be a good place to start, at least they'd entertain the same values. I'll try to cut some fuel out and see if i can tame these AFR's. Timing's at 15 BDTC so it's pretty safe..

I'll keep you all posted.

[nelsonmxmarc]

Ok so the MAF is physically fine and working 100%.

Mitch came over with another z32 maf last night and it wasn't reading right, so we put mine back in and measured the voltage, checked out okay.

So basically everything was down to the tune.

We took it out on the road - again running lean due to the z32 maf and my latest tune.

Basically we ran the AFR's into the ground; Less than 10 AFR on the maps, this finally enriched the car enough to drive on boost, which we did with no issues!

So the car IS running 100%, the tune is definitely in need of work, and the AFR maps are ALL below 10 to compensate for the lean condition..

This ultimately leads me to believe that, due to the scaling on the maf not being set properly from the start, it's not accounting for the extra voltage on the thermister, and the ecu is being relayed a lean condition..

At least now we've come to the conclusion that my car is in 100% working order - relief.

[nelsonmxmarc]

http://forum.nistune.com/viewtopic.php?f=7&t=914&start=0

Yup

[beacher1B0]

Have u thought about puttin your tune and a Log up on Nistune?

[M13]

Have u thought about puttin your tune and a Log up on Nistune?

THIS.


try nistune forums for better guidance. GTRC can't help you much on this haha.

[nelsonmxmarc]

Im praying that tomorrow, he can resolve this issue on the dyno, otherwise that's EXACTLY what i'll be doing lol. Ugh, keeping my fingers crossed..

[beacher1B0]

The members on Nistune Forums are really good. They always seem to be really helpfull.
Put up a Log and/or your tune just to see what they say.