Engine - Hard Start Or No Start

File In Section: 6E Engine Fuel & Emission

Bulletin No.: 66-63-09

Date: April, 1997

Subject:
Engine Hard Start or No Start (Replace Fuel Pump Pulsator)

Models:
1992-96 Chevrolet and GMC Trucks
1992-96 Oldsmobile Bravada
with Gasoline Engines

Condition

Some owners may report their engine is hard to start or will not start.

Cause

The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator. The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol.

Correction

Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks. If the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised.

Part Information

P/N Description Qty

25175836 Damper Asm - Fuel Pulsator 1

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty. use:

Labor Op Description Labor Time

Use Published Labor
J 5590 Pump, Fuel R&R Operation Time

Important:
Labor operation is coded to base vehicle coverage in the warranty system.