TROUBLESHOOTING GUIDE
F2-63flowchartTroubleshooting Guide (continued, STEP 5–7)
1
STEP 5: Is fuel line pressure correct at idle? (page F2-113) Fuel line pressure: 260–310 kPa {2.5–3.2 kgf/cm2, 37–45 psi} (Vacuum hose disconnected from pressure regulator)
No
Low pressure: Check fuel line pressure while pinching fuel return hose. If pressure quickly increases, check pressure regulator (page F2-113). If pressure gradually increases, check for clogging between fuel pump and pressure regulator. If hose is not clogged, check fuel pump maximum pressure (page F2-110).
Low pressure: Check fuel line pressure while pinching fuel return hose. If pressure quickly increases, check pressure regulator (page F2-113). If pressure gradually increases, check for clogging between fuel pump and pressure regulator. If hose is not clogged, check fuel pump maximum pressure (page F2-110).
Yes
2
Does fuel line pressure decrease during quick acceleration? If it does, check for clogging between fuel pump and pressure regulator. If it does not, go to next step.
go to next step
3
STEP 6: Is cooling system OK?
No
Repair or replace: Thermostat, Electric coolant fan, Radiator (section E)
Yes
4
STEP 7: Try a known good ECM; does condition improve? (page F2-141)
No
Change to another brand of fuel or use a higher-octane fuel
Yes
5
Replace ECM (page F2-141)