Diesel Injectors - Rough Idle, Smoke, Poor Performance,

84pontiac07

Number 83-I-185 Section 6B Date 4/85

Subject: DIESEL ENGINES WITH PLUGGED NOZZLES

1980-83 MODELS EQUIPPED WITH 4.3L V-6 OR 5.7L V-8 DIESEL ENGINES


Diesel injection poppet type nozzles on some 1980-83 models may become plugged with carbon to the point where performance may be affected. This may show up as a rough idle, smoke, reduced performance, loss of fuel economy, etc. Poppet nozzles used on 1984-85 models are of semi guided design, and have not shown a tendency to plug.

The plugging condition can be greatly reduced if not eliminated with the addition of DEXRON(R) II automatic transmission fluid to the diesel fuel. Add two quarts of DEXRON(R) II automatic transmission fluid to the fuel tank, then fill with diesel fuel.

Advise the customer to drive the vehicle until the fuel level is less than 1/4 tank before adding additional diesel fuel. Do not add additional transmission fluid. If carbon accumulation was responsible for the driveability condition, this procedure should correct it. If the condition is not corrected, additional quantities of transmission fluid will not correct condition. Refer to the diesel injection nozzle testing procedure and the diesel engine diagnosis section in the appropriate Chassis Service Manual.