Prizm L4-108 1.8L DOHC VIN 8 MFI (1998)
6. This step checks the fuel pump for a worn bearing or a binding impeller. The pump should have a smooth and steady low humming sound. A loud
humming or growling noise may indicate a faulty fuel pump. Check a known good vehicle in order to compare pump operation.
12. The fuel system can not maintain constant fuel pressure with a leak in any of the following areas:
^
The fuel pump check valve
^
The valve or valve seat within the fuel pressure regulator
^
The fuel injectors
17. This step checks whether the fuel system is leaking between the fuel pressure gauge and the fuel injectors or between the fuel pressure gauge and
the fuel sender assembly.
20. This step checks for additional conditions that can cause low fuel pressure other than a faulty fuel pump. Check for any restrictions or blockage in
the fuel feed lines and hoses, including those inside the fuel tank. Check the fuel pump electrical circuit for excessive resistance. Proper fuel pump
operation requires correct voltage and adequate current flow.
23. Check for rust and other foreign materials in the fuel tank. Clean or replace as necessary.
