I've got a 97 GSX and we just rebuilt the whole 4G63 engine because one of the balance shaft barings went and caused havoc inside the block....we used the shaft eliminator and put a stubby shaft in had the whole head redone professionally and put it all back together. With acceleration it runs great but when idle it runs like crap...

Here is a video of what it sounds like when idling and some slight acceleration

http://www.youtube.com/watch?v=qq_L--bZsuo

We replaced the fuel filter and cleaned the injectors still the same issue....Took off the MAF sensor and that's working fine...

It smokes a bit and sort of smells like unburnt fuel blue smoke we figure is from all of the cleaning crap we put in it while rebuilding it....

We're at a loss as to why it's so crappy on idle does anyone have ANY ideas????

 

I forgot to add this is a turbo 4G63

 

sounds like you are running super rich. I this only while the car warms up or after its is warm? It could have something to do with the fuel pressure. Or even something like the Throttle position sensor not be calibrated to the correct voltage.