need helppp

ok so heres the problem..i have a 91 SL manual...problem started when i would be driving, id slow down to go around a turn depress the clutch and start turning the car would stall out...now its gotten to the point where i start it and its barely holdin on for life and then itll die...ive read up about all these problems and determined it to be a possibility of 3 different things which i changed/cleaned. first i took out the ISC found it to look pretty clean didnt really know much to do with it though so i cleaned it a bit then put it back in...nothing changed...i also changed the ECU, and the MFI to no avail..im thinking about just changing the ISC to see if thats it but if not does anyone else have any other suggestions? thanks for any input.

ok so heres the problem..i have a 91 SL manual...problem started when i would be driving, id slow down to go around a turn depress the clutch and start turning the car would stall out...now its gotten to the point where i start it and its barely holdin on for life and then itll die...ive read up about all these problems and determined it to be a possibility of 3 different things which i changed/cleaned. first i took out the ISC found it to look pretty clean didnt really know much to do with it though so i cleaned it a bit then put it back in...nothing changed...i also changed the ECU, and the MFI to no avail..im thinking about just changing the ISC to see if thats it but if not does anyone else have any other suggestions? thanks for any input.
If its only happening when your turning the car and the other stuff checks out it may be fuel related. A clogged fuel filter could possibly do it.