ka24de a/f ratio problem please help!!

[neongreenglo]

ok my car was turbo'd by the previous owner who put a piggy back safc on it and leaned it out and scorched a piston so i got a newer rebuilt ka from one of my customers and the motor ran great when i pulled it. i put it in my car new plugs and wires, oil and fuel filter. she started right up but she runs rich. i have a a/f gauge in my car and it will rev threw redline with no problem but it wont hold constant rpm's like i try to rev it at 2 or 3k and hold it there, and it cuts out and wont run and my engine shakes violently i've swapped maf 3 times and even swapped computers with the computer that was in the car the motor came out of and when i swap the computers the other one makes it run really lean and still has same symptoms will rev threw redline and sounds healthy but wont hold rpm's any ideas? the only mods on the engine are egr block off plate and a full megan exhaust 3 inch from header back

[neongreenglo]

BUMP!! C'MON GUYS I'M STUMPED!

[danielsan]

clean out the fuel pump sock filter.

could be an injector its a common problem with these cars.

[Rucca]

Vacuum leaks, fuel pressure, wiring problems.