S14 SR20 help! Over fueling

[808_silvia]

Well I've done lots of searching and trouble shooting for months now and can't seem to get this car running smoothly again.
I have freshly rebuilt the top end of my sr20.
List of upgrades after rebuild:
S14 sr20det
Hks step 1 256 cams
740cc injectors
Z32 maf
Rs enthalpy tune

I can't figure out what else is wrong so please help me on this one. Car idles normally but sounds like its missing a couple times a minute. When I go to rev the car, it sounds like it being over flooded with gas. But if I keep revving it, the excess gas seems to get burned out and I can rev the car like its running perfectly. But once I let it go back to idle and try revving it again, it starts to bog again. Spark plugs are fouled and black smoke coming out the exhaust.

List of things I have checked:
Compression- 150psi across all four
Timing- set to 15*
Checked for vacuum and boost leaks
Changed out mafs with another z32
Maf wiring should be correct and I can rev it throughout the whole rev range

Last thing to check is the injector o-rings.
Would leaking o-rings cause this though? The car starts up fine and idles nicely, just has a hard time revving it up. Martin at enthalpy has been helping me out a lot but I need to get this car running asap. It ran perfectly before the rebuild but after is when all of this started happening.

PLEASE HELP, this is my daily

[BadazzSr20]

something in the tune is messed up that what it sounds like to me. To much fuel on low rpms being u dont have a standalone and u have sr20 is a self learning ecu it seems to me that ur ecu is trying to correct fuel and its fighting with ur tune to ajust air flow and fuel and it making it to run rish.

Try contacting the programer of ur tune and explain go him so he can reajust the tune for u on ur lower rpms.

[SuperBlackS14]

Should probably post an intro, forum rules and all that. Good luck otherwise.