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Fuel System Leak: Low Pressure and Fuel-Injector (CPI) Repair A Chevy Blazer with low fuel pressure and "reluctant" start-up gets a fuel system repair. From "Weekend Mechanic" episode WKM-408

In this project, Weekend Mechanic host Bruce Bonebrake diagnoses and repairs a fuel delivery problem on a 1997 Chevy Blazer that's having difficulty starting. After the vehicle fails a fuel pressure test, Bruce checks for and finds fuel leaks inside the upper intake manifold where the CPI unit is located. He replaces the fuel injection CPI assembly and retests the system. A test drive confirms the successful repair.

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	The new fuel-meter body
	The fuel injector

Project Overview

Bruce tests the fuel injection system on the Blazer using a fuel pressure gauge that also measures fuel flow. He then disassembles the system, removing the air ducts, upper intake manifold and the CPI unit. (CPI, or Central Point Injection, is a GM fuel injection system. He locates a leak in the CPI unit fuel-injection line. Bruce cleans the upper intake manifold, replaces the fuel injectors and reassembles the system. He also replaces the ignition coil, the PCV valve, a cracked vacuum hose and all of the seals. Finally, Bruce retests the fuel system, installs a new fuel filter, and test drives the car to verify the repairs.

DIY Difficulty Rating for the Project: This job requires getting into the engine and disassembling some components to find the source of the problem. We gave it a difficulty rating of 3 on a 5-point intermediate-level scale. We allowed eight hours for this repair.

Important: Included here is a basic summary of the steps in this automotive procedure as shown in the episode. These steps are general guidelines that are applicable to most vehicles. With any particular vehicle, there may be procedures, specifications, settings, tolerances, components, etc. that are specific to that vehicle. There are also variations according to the type and brand of repair-kit or replacement parts you select. Always consult your vehicle's service manual when undertaking significant automotive repairs, and read and follow the manufacturer's directions and precautions that come with your kit or replacement parts.

Fuel pressure gauge

Tools and materials:

In addition to standard auto-mechanic's tools (wrenches, ratchets, extenders, screwdrivers, nut-drivers, torque wrench, etc.), some of the tools required for this project include

fuel pressure gauge
carb cleaner
fire extinguisher
safety equipment

Safety Alert: Always wear eye protection and ear protection, and follow proper safety precautions, when working with power tools. Also wear eye protection any time that you are working beneath a vehicle or around toxic or caustic fluids.

Safety Alert: As a standard safety precaution, always disconnect the vehicle's negative battery cable before you begin work on any electrical or mechanical components.

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