SR goes lean for a second under throttle

[Beems240sx]

S13 SR20, S14 "WC" ECU, front mount, hks bov, isis intake manifold, 3in exhaust, 14psi, 18 in vacuum

i noticed this about a week ago, it started to bog when i gave it gas. at idle my AFR gauge will be at 14.7-15.1 like normal. then ill blip the throttle and it will bog and read about 17, which is WAY lean. after that initial bog it will rev to 7K without a hiccup with perfect AFR throughout. this will happen at any rpm, say 2nd gear crusing at 4K rpms, punch it and it will go lean for a second then back to normal. it is more intense when the motor is semi-cold and gets hard to actually drive it. it is NEVER lean underboost and pulls hard.

im leaning towards the MAF, i will be testing the maf for correct voltage to the ECU. another thought is the ignition timing as i couldnt seem to get it to work with my timing light correctly so its just "close enough" and lastly is the FPR or fuel pump. but since all other afr's are correct im not so sure on those.

[Beems240sx]

Any ideas guys?

[Beems240sx]

So I messed with it a little bit this weekend while working on the 300zx brakes. I swapped out my tps for my spare one, still no change. And I clamped off the iacv incase it was leaking, still no change. I still need to check maf voltage and my 02 sensor

[USMCgetsome]

check that map and your gonna need to do some data logging to find out if a sensor is dropping out or if the injectors/coil packs aren't keeping up. You got a problem and your doing a great job of investigating

[Beems240sx]

I have a question about the 300zx maf. I'm running the s14 sr ecu and I need an s14 sr maf. Now I know I can use an s13 sohc ka maf with a potentiometer. Why don't people use the potentiometer with the 300zx maf? That would seem like the logical choice. All the ecu cares about is seeing the correct voltage to it. In reality any and ever maf could be used as long as you adjust the voltage.

Hopefully next week ill be running Nistune also, so I will be able to data log with afr's

[USMCgetsome]

IIRC you have to use the stock maf or ka maf but the z32 i believe needs a piggy back or aftermarket ecu.

[Beems240sx]

Ok I got an s13 sohc ka maf on the way. All I need to do is pick up a potentiometer from radio shack and hopefully it will solve this problem