i think ive tried everything folks and to no avail
my summer project is still kicking my butt
i have replaced cats, ecu's, maf's and vacum hoses
and i still have the same issue of the damn thing will not rev past 4k and is kicking black smoke from running extremely rich, i just have a few final questions before i totally give up , as this project has me to the point where i am doubting myself and what little mechanical skill i thought i had gained.
1 can the idle air control valve be completely removed without harming functionality of the motor?
2 if the fuel return line is too large would that cause a rich condition in the engine
3 what would cause the maf and iacv to not communicate with the ecu?
im officially stumped with this project daily driver please anyone, i really need a direction to go in
thanks

 

what year is your SC..

 

running rich, i could think of ignition coils going bad, o2s are bad. timing probably may be off.

 

the motor is from a 97 sc400 and its obd2
also its throwing the mass air sensor wiring code

 

Thats probably the problem you have there which is why its not revving pass 4K...

+1 on the timing.

 

I see you say the motor is from the97 sc400, is that your car or is your car a different year?

 

different car alltogether the motor is in an 87 supra but the motor ecu and wiring harness all came out of the same 97 sc400
to my knowledge the wiring issue that the the code is describing is one in the factory wiring harness that i havent touched

 

sounds like it could be ignition coils, change them both and see, their cheap and cause that sort of issue.

 

hey heres a link to the video i just made showing whats going on with the car
http://www.youtube.com/watch?v=WjRpHaA64sY

 

damn that sounds like crap lol. sounds like ur gonna need to replace that PS pump soon also lol.

sounds fine idling, but i do think ur timing might be off. remove the cam covers and check the notches.

 

Prolly have the wrong air flow meter. My buddies s14 did the same thing. Try changing the maf