Diesel Engines - Hard Start, Erratic Operation, Smoke
NUMBER: 86-B-32GROUP: 6A - Diesel Engine
DATE: January, 1986
SUBJECT:
DIESEL FUEL INJECTION PUMP ADVANCE PISTON
MODELS:
1982-1985 C, K, G, P WITH 6.2L DIESEL ENGINES
Some vehicles equipped with the 6.2L diesel engine may experience conditions such as loss of power, hard starting, erratic engine operation, and excessive black or white smoke. Refer to Truck Service Bulletin 84-B-74 for fuel system diagnostics. If on-vehicle diagnosis indicates that the injection pump is the problem, a worn or binding injection pump advance piston may be the cause. A new nickel-plated advance piston has been introduced on the 1986 6.2L diesel engine. This nickel-plated advance piston reduces piston/bore wear and piston seizure. This piston has been made available through Stanadyne Diesel Systems dealers as a service part for 1982 through 1985 6.2L diesel fuel injection pumps. Installation of the nickel-plated advance piston must be requested by the GMC dealer when the pump is sent to the Stanadyne dealer for repair. Stanadyne Part Numbers:
Description P/N
Nickel-plated Advance Piston (Standard Bore) 27865
Nickel-plated Advance Piston (.008" Oversize) 27869