Trobleshoot and fix A Chevrolet Z71 Fuel System

Chevrolet's Z71 engine is used in its heavy-duty contour of trucks liking the Silverado, Avalanche and Tahoe. Any problems with this engine's fuel system can completion in wasted fuel and increased pollution, or it could create the Motor lorry not bound at all. Whether you are looking to trial your Z71's fuel system for problems, you should expressly probation the fuel vigour. Problems in the fuel pump, filter or power regulator can prompt to problems here.


1. Turn the ignition guide on with the windows up. Listen for a soft, petty whirring sound--it might lasts for aloof a moment or two. The pressure should be 60 to 66 pounds per square inch for a V6 engine. On V8 engines, the pressure should be 48 to 54 psi for engines that take E-85 ethanol gas and 55 to 62 for the others.7.

Trial the wiring to the fuel pump whether the fuse and relay are positive. Provided the wiring is skilled besides, you possible corner a dangerous fuel pump.

3. Corner the Powertrain Government Module (PCM) checked provided the fuel pump runs continuously while the ignition explanation is on. The PCM should sole be looked over by a adequate assistance or repair shop.

4. Aid the power from the fuel step before proceeding very. Unscrew the fuel cap and remove the fuel pump relay from the fuse box. Eccentric person the engine for a uncommon seconds and wait for it to begin and quickly stall (or it might not engender at all).

5. Connect a fuel pressure gauge to the fuel pressure test port on the fuel supply rail (remove the port's cap). The gauge needs an adapter that will connect to the test port's Schrader valve.

6. Turn the ignition key to the "On" position. Check the pressure on the gauge. Provided you hear this sound, it wealth the fuel pump is working. Whether you don't hear it on the inside, listen for it on the away; remove the fuel filler cap, depress the spring-loaded door in the filler neck and keep someone else turn on the ignition while you listen.2. Whether you don't hear the fuel pump, trial the fuel pump fuse and relay within which are located in the engine fuse box.

Check for restrictions in the fuel system, including the fuel filter and inlet strainer, if the pressure is lower than it should be. If there are no restrictions, you likely have a bad fuel pressure regulator or fuel pump. Replace the pressure regulator if the pressure is higher than specified.

8. Disconnect and inspect all lines in the fuel system, including the fuel supply and return lines and the Evaporative Emission Control vapor lines. Replace any lines that are dry, cracked or leaking. Look for any dirt in the lines and blow it out with compressed air.