Engine - Excessive Black Exhaust Smoke, No Power Test

Number 83-I-36 Section 6B Date 01/83
Subject: EXCESSIVE BLACK EXHAUST SMOKE AND NO POWER - 1983 6000 EQUIPPED WITH A V-6 DIESEL ENGINE
Some 1983 6000 models equipped with a V-6 engine, may experience a condition resulting in excessive black exhaust smoke and no power. An inoperative vacuum regulator valve, which allows full time EGR and EPR, could be the cause of such a condition. To test the vacuum regulator valve, install a vacuum gage at the vacuum outlet port of the V.R.V. leaving the vacuum source connected at the inlet port. With the engine running, note the vacuum readings while changing the throttle angle. The vacuum readings on a good vacuum regulator valve should raise and drop with changes in the throttle angle.