93 gsx misfire, need help 93 gsx Options

[doayamaha]

ok my friend has a 93 gsx and it is upgraded bigger turbo, fmic, s-afc. the other day we were doing some cleaning up of wires on the inside of the car afc wiring and removed indiglo guages. but when we got done doing that we took it for a ride to make shure everything was working correctly. every thing was fine then we decided to take it back to the shop and put it on the lift to check everything under it. when we took it back off the lift went to leave the shop and something was wrong. kept on creeping up to being rich and idled high when you would take off just as you start to get into boost it starts stumbling. but once it gets boost built up it takes of like nothing is wrong untill you stop and it does the same thing. any help i could get would be very helpfull.

[awd4kicks]

This is like dejavu! I'll try a different apoach this time.

Have you checked it for boost leaks? I can imagine a gap in the piping or intercooler that releases a lot of the incoming air, until the 'big' turbo gets cranking hard enough to build enough pressure for the engine to seem normal.

It's just a thought and for this to happen it would have to be a gap that does not increase with boost. Otherwise the theory for this diagnosis will not hold water.

This happened to me when I blew out one end of my FMIC. The turbo could still build like 5 psi even with a huge gaping hole in the intercooler.