Mitsubishi Repair: 95 eclipse, air fuel ratio, crank sensor

Question
1995 eclipse, 2.0, GSX manual.  This car stalls out at 3500rpm.  It runs fine up until then, then stalls.  With your foot on the gas, if you keep it at 2000 it will stay running but if you take your foot off the gas it will stall.  We have changed the fuel pump, fuel filters, one sensor on the throttle body (top sensor), crank sensor,cylinoid(both on the firewall), pvc??? vac line??.  We pulled the plugs and there was like a black sut on them after only a month (splitfires). Any ideas? Where do we go from here?

Answer
Sheila,
Black soot on the spark plugs, also called carbon fouling, is caused by your engine running too rich.  Which means your air/fuel ratio has too much fuel and not enough air for the engine to run properly.  Too much fuel can choke your engine at higher RPMs and cause stalling.  This may be an indication of an emissions component not functioning correctly, like your oxygen sensor.  It could also indicate there is a clog in your air intake system somewhere.  Your best option is to have your local mechanic inspect your intake, fuel, and emission systems to see if they can pin point the problem.
Good luck!