Need Help 91 FC-NA~problems\running rich
 

Hey guys trying to help my buddy fix his 7, I have a Miata and I'm not too great with the rotary. Anyways, his problem started late this summer- first with a/c -on- the car would drop idle. 2-4wks later his car died. Check engine lt was -on- ->bad TPS and MAF code. Changed out with brand new TPS and MAF sensor- check engine lt now -off-. Car runs but not good- poor accel - and he has to keep foot on throttle to keep running @ stop even after warm up.
-Car has about 75k~ was only driven in summer by prev. owner (a grandpa:))stock/well maintained.--> He has had it for 5x yrs now- the car has never been pushed, but has minor mods- exhaust and intake. He uses Valvoline durablend oil. (?-if good for seals or not)
-Got comp. test done by Mech. -front rotor 1.5.6, 2.5.5, 3.5.5 KPI@260rpm
back rotor 1.4.6, 2.4.2, 3.4.5 KPI@260rpm - Mazda tech. said meets minimum specifications.
-Car will not pass emissions due too fuel being too rich/fuel not being burned.
-Mech. checked fuel pressure - said it was good (im not sure of PSI)
-he has the 460cc injectors-and they have never been serviced.
-Coil pacs good and getting spark - (new NGK plugs)
--->I was thinking it might by IAC - but can't really find the symptoms of bad IAC(or BAC) for the 7 or how to test it...or even the ohm specs.(his DA doesn't have a Haynes:o)
Anyways, Please HELP any useful ideas welcome - he told Mazda this and they told him just needs a new/rebuilt engine... That can't be right-> a NA 13b w/ 75k.