Thread: Apexi SAFC & Neo Problem

SO Ive been using a Apexi SAFC for over a year now on my 96 200sx SE-R never had an issue works perfect for tweaking fuel

Finished my Gti-r Miata swap but had an issue with it being Lean on Boost
after troubleshooting for weeks figured i could use the SAFC just like in the 200sx
Bought a Apexi NEO hooked it up but when i went to adjust fuel i Got NO change whats so ever no matter how much i tried to increase

Figured it was broken so i removed it and installed it on my 200sx to my surprise it worked perfectly so it wasn't broken

so instead i hooked up the SAFC to GTI-R Miata and see if it would make a difference but no
i got the same issue no matter how much i increased the fuel i got no change and it still remained Lean on Boost

Has Anyone ever had an issue like this?

Maybe the fuel pump is not able to keep up?

Lean on boost means ECU is not adding enough fuel for the amount of air that is going through the engine.

So let's think this through - possibilities could be:
1. MAF is not reading all the air going through it?
2. O2 sensor is not reporting to the ECU correctly?
3. Lack of fuel or fuel pressure

Would not be a vac leak as under boost you would have a rich condition.


You need to get hold of a scan tool, Nissan Consult or at least a Techtom so you can see what the sensors are reporting to the ECU and when.



Fuel lines backwards (I know I already said this in a PM)?

Fuel Pump -> Fuel Feed Line -> Fuel Filter -> (Optional Fuel Pressure Gauge) -> Fuel Rail-> Fuel Pressure Regulator -> Fuel Return Line -> Fuel Tank


What MAF (Can't find where you answered that in all the PMs)?

Where is MAF Located - How far from TURBO inlet?

What MAF/Air Filter adapter are you using - is it blocking the small hole in the MAF at all?

Like I said previously - Call me. I would really like to see this setup work.

Will try to Call u As soon as i get a chance, get of of work late

I have a Z32 MAF on right now but i have also tried the original and several others just to make sure it was not damaged



Ill write up a complete list of what was done later on along with pictures

Z32 MAF on an UN-modified N14 ECU - Am I the only one seeing a problem here?

Let's say that a Z32 MAF will allow the same amount of air through that a 54C will - The problem is that it will report that same amount of air to the ECU with a much lower voltage than the 54C will because it is capable of reading more air.

if he's running the afc neo he can run the z32 maf. I got a stock p10 ecu on my b14 ve running a n60 maf with the afc neo, but if he removes it he will need the stock maf.

lol... the ecu is a Nismotronic chipped ECU with the base tune for a Z32 MAF given by nismotronic when i purchased it

I also tried the original ECU with the Original MAF and the result was the same

Its not a stock ECU its Nismotronic with a base tune for a z32 MAF

Last we talked everything was stock - this is not the case.


Get it running in the stock configuration and go from there.


Stock 54C MAF
Stock 54C ECU
MAF at the turbo inlet
Stock RE-Circulation valve recirculating

Etc...


i know you are limited on space but if ran good in the N14 Clip, there is no reason it should not run good in the Miata