checked vacuum lines,they seem ok. check engine lite is not on,but the coolant lite is. coolant is full in radiator and the reservoir. started black smoking, bad egr maybe?
engine revving up on 1992 Mitsubishi Diamante
Black smoke is from too much fuel, not EGR. You may have excessive fuel pressure, bad mass airflow meter or a bad injector. Even though the check engine light isn't on, check the codes, there may be one stored.