Turbo 95 going EXTREMELY lean (23.8) under tip-in
 

INFO about car:

95 Running MSPNP2
99 Swap
6 speed
BEGI S4 Turbo Kit (mostly) with GT2560
Innovate LC-1 with week old sensor.
Stock Coilpacks
Rather New NGK Wires
MSM Plugs with the stock gap (.040?)
550cc injectors - TLFPerformance - under warranty.
No MAF, only IAT.

Okay. As of Sunday I didn't have this issue. Nothing has changed in the engine bay or tune. I did a track day that day and by the end of the day I was having a tip-in stumble and some idling issues. It was very slight, but noticeable. I drove the car home fine with 0 issues.

Monday it got slightly worse.

Tuesday it got pretty bad.

Today was hardly driveable.

When I tip into the throttle, it will go lean for 5-6 seconds before it finally gets fuel and goes again. All other sensor readouts are normal: MAP, CLT, RPM, TPS, everything! There are no corresponding readouts that would cause this as a symptom. (To my knowledge)

Overrun Fuel cut makes no difference whether it is on or off.

My options so far are to

a.) test the fuel pressure - possible pump failure
b.) replace the fuel filter

These seem like an unlikely cause though, since it only happens at tip-in. If I haul ass in the car it still runs pretty damn good. AFRs are good too.

Screenshot:

https://www.miataturbo.net/attachmen...ine=1368073662

LINK TO DATALOG>> CLICK HERE For some reason the upload fails every time I try to upload even though it is within the size constraints.

get the log posted.

Okay. The datalog is posted. It is hosted on Google drive, so just click the link and you can download it.

The upload fails every single time even though it is within the size limit.

Wow! what a smooooth map reading. Looks like map sensor is very lazy, propably due to clogged, pinched vaccuum line or if you have an inline filter to this line , it is way too restrictive... Map readings usually are more responsive than tps readings. Your log shows the opposite.

That would make sense. My gauge was reading fine but it is on a different vacuum port, so I will chase down the map sensor side after work tonight.

Bingo! Awsome catch man!

Always nice when its super simple fix