DIY Network

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

(Continued from page 2)

Our fuel injection system is know as a CPI assembly consisting of the fuel meter body and six injectors and lines.

Weekend Mechanic Expert Tip: The CPI injection system varies depending on the model year of the vehicle. Be sure to properly identify which style CPI system your vehicle has when ordering the replacement part.

• Before installing the new injectors into (figure F) the new fuel meter body (figure G), it's important to lubricate them so they fit into the cavities easily.

  Figure F

  Figure G

  
  

• Align the raised lug on the injector base with the notch in the fuel meter body cavity, and push the injector in until it's firmly seated in the body.

• Continue installing the fuel injectors into the fuel meter body (figure H), using automatic transmission fluid or light engine oil to lubricate them (figure I).

  Figure H

  Figure I

  
  

  Figure J

• With all of the injectors installed, the retaining plate goes onto the fuel meter body and the nuts are tightened down.

• The fuel pressure regulator is installed onto the fuel meter body and the retaining clip holds it secure.

• A new O-ring seal is installed onto the fuel meter body (figure J). It's given a light coat of oil and the fuel meter body is installed, snapping it into place.

• The poppet ends of the fuel injectors are installed into the individual cylinder ports and the installation of the new fuel injection system is complete.

• Before re-installing our cleaned upper manifold, we give it a nice coat of engine paint. When it's dry, install a new seal, seating it well into the groove.

• The beautifully painted upper intake manifold goes into place and the mounting bolts are tightened down to specifications.
  

  Figure K

• The new fuel line assembly is installed onto the injection body (figure K).

• The retainer plate goes on and the fasteners are tightened down.
  

  	The PCV valve
  	The fuel meter body, installed

• The new throttle body seal goes on and is well seated in the groove. Re-install it onto the intake manifold.

• The bolts go in and are tightened down. To replace the leaking ignition coil, disconnect the ignition module and the ignition coil connection. Loosen and remove the bracket bolts and remove the bracket and old ignition coil.

• Our new ignition coil and bracket goes in and the mounting bolts are installed and tightened down.

• The ignition coil connectors are re-installed. And the new ignition coil should be good for years to come.

• After the throttle brackets are re-installed, the throttle cables are connected and the throttle cables and "butterfly" are working well.

• Our old PCV valve is clogged and leaking oil so remove the old valve and replace it with a new one.

• The PCV valve and line are installed onto the valve cover and the intake manifold port.

• Next remove the old, cracked vacuum hose. Replace it with a fresh hose and connect it to the intake manifold. The other end is connected to the check valve. Secure the hose using zip ties.

• Under the car, disconnect the fuel line and remove the old filter. It's important to have a catch basin and rags to soak up any spilled fuel.

• Safety Alert: Remember to have a fire extinguisher handy and wear safety glasses when working on the fuel lines.

• After disconnecting the pressure tester adapter the fuel lines can be connected to the new fuel filter and the bracket and fuel lines are tightened down.

1 | 2 | 3