Originally Posted by AJZax

If you have a leak after the MAF (turbo, chargepiping, intercooler, bov, manifold etc.)
in vacuum the engine is sucking in air that isn't metered by the MAF. Therefor the ECU doesn't know about some of the air going in, so it creates a lean condition. This is reversed when there is positive pressure as there is metered air leaking OUT of the system. That makes it so the ECU is putting fuel in for air that's not there.

ISIS MAF should be ok. Hell we dynotuned a stock S13 SR with an "ONLYMAF" ebay maf (haha I cautioned him against it). But Martin dynotuned it and got 258whp out of a t25 370cc setup. Then after it we got 255whp out of another stock SR using a JECS OEM N62 MAF. (obviously the MAF didn't make the power difference, it is simply showing that both mafs did the job).

The hot wire element in the ebay MAF was a weird coiled spring instead of the antenna looking element of JECS.

Realize a hotwire maf is simply a wire that is heated by the system to create resistance. So your 5V signal through the MAF is resisted down to .45V or so, and as air flows through it it cools the wire, reducing resistance and increasing voltage. This works realyl well as it accoutns for temperature and air density changes and can accurately meter air MASS instead of using a calculation. This is why OEMs use MAF instead of MAP on turbo application.

-how sure are you on those injectors? (can you try known good sr 370cc injectors from a running stock SR?)
- boost leak test
- test fuel pressure