K 2500 Truck 4WD V8-379 6.2L DSL VIN C FI (1989)
Fuel Pressure Regulator: Customer Interest
Fuel - Hard Starting Cold
GMC NUMBER: 89-6A-139
GROUP: 6A Engine Mechanical
DATE: October, 1991
CORPORATE NUMBER: 036306
SUBJECT:
HARD STARTING COLD (INSTALL NEW REGULATOR VALVE ASSEMBLY AND PUMP)
MODELS:
1982-89 ALL TRUCKS WITH 6.2L DIESEL
Some 1982-89 trucks with 6.2L diesel engine may experience a cold hard starting condition. This condition may occur even though the glow plug system
is operating properly.
The cause of this condition is air leaks in either the return or suction side of the fuel system. These air leaks cause loss of fuel prime in the injector pump
after engine shutdown.
SERVICE PROCEDURE:
On the return side, a new HPCA (Housing Pressure Cold Advance) regulator valve assembly, P/N 10149645, must be installed. This valve and seal
replaces the existing ball check regulator valve in the injector pump. On the suction side, install a new fuel pump, P/N 25116503, which now uses a new
ventless check valve to prevent fuel drain back.
Both the return and suction side must be corrected at the same time. This correction is for all 1982-89 trucks except 1988/89 C/K trucks which use an
electric pump with integral check valve. We still require replacement of the HPCA valve on the Stanadyne injector pump.
Parts are expected to be available on October 21, 1991. In case of limited inventory, parts will be placed on 400 Control to waive VIP surcharges. Only
verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. However, the part will be shipped premium transportation
at dealer's expense and all other order types will be placed on backorder until the 400 control is removed.
Use applicable Labor Operation and Time.
