TROUBLESHOOTING GUIDE — 26 POOR FUEL ECONOMY (continued)
F2-67flowchart26 POOR FUEL ECONOMY — Troubleshooting (continued, STEP 6–10)
1
STEP 6: Are ECM terminal voltages OK? (especially 2B, 2C, 2D, 2E, 3U, 3V, 3W, 3X, 3Y, and 3Z) (page F2-141)
No
Check for cause (page F2-141)
Yes
2
STEP 7: Connect System Selection to data link connector and set Test Switch to "SELF-TEST"; is ignition timing at idle correct after warm-up? (page F2-70) Ignition timing (BTDC): 9–11° {10 ± 1°}
No
Adjust ignition timing (page F2-70)
Yes
3
STEP 8: Is fuel line pressure correct at idle? (page F2-107) Fuel line pressure: 210–260 kPa {2.1–2.7 kgf/cm2, 30–38 psi}
No
High pressure: Is vacuum hose to pressure regulator damaged or poorly connected? If it is not, replace pressure regulator (page F2-115). If it is, repair or replace vacuum hose.
High pressure: Is vacuum hose to pressure regulator damaged or poorly connected? If it is not, replace pressure regulator (page F2-115). If it is, repair or replace vacuum hose.
Yes
4
STEP 9: Run engine at idle; does fuel line pressure held after ignition switch is turned off? (page F2-107) Fuel line pressure: More than 150 kPa {1.5 kgf/cm2, 21 psi} for 5 min.
No
Check fuel injectors for fuel leakage (page F2-116)
Yes
5
STEP 10: Change to another brand of fuel