exact post from mazda-speed.com
help me please

ok this only happens randomly and has no pattern. sometimes after, during or when i first start my car, my RPMs will kind of "wiggle" down below normal and acts like it wants to stall. problem one. next problem which prolly has to do with this, it does that **** sometimes when i start it up then i will rev it and its fine then when i try to drive away from my house it bogs i guess like i can be in frist gear and it will just act like it wants to stall i can floor it and it just stays at the 2000 or so rpms and acts like it wants to stall. so i rev it up and take off. idk what the problem is but if you could help that would be awesome. if u don't know my car 93 miata greddy turbo, bov, bipes acu, and manual boost controller thanks bye

 

Switch out your AFM with a known good one.

 

that or a vacuum leak.

 

have you switched to larger injectors?

 

are you running a cat? i had that same problem and it turns out my cat was dead and clogged with sumthin. but like olderguy said i would switch the afm with a friend and see if that works.

 

mmk the bipes acu is very well known at mazda-speed.com 9 out of 10 people recomended it. its the best buy for the $250 that it is it retards up to 16 degrees and increases air flow retards by air temp. and different rpm maps so its a very nice unit.. but i have cheacked for vacum leaks there are none.. my CAT is about two monthes old so i'm not sure it was a universal one so that could be the prob.. i'm thinking the next thing i'm doing is a nice exhaust would u guys agree. then get an intercooler..

 

we are very well versed in the bipes thank you.

how is your BOV routed?