TROUBLESHOOTING GUIDE — 4 CRANKS NORMALLY BUT WILL NOT START (PARTIAL COMBUSTION) — AFTER WARM-UP
F2-25flowchart4 CRANKS NORMALLY BUT WILL NOT START (PARTIAL COMBUSTION) — AFTER WARM-UP
DESCRIPTION: Engine cranks at normal speed and shows partial combustion but will not start after running and being hot soaked. Battery is in normal condition. Engine starts normally when cold.
NOTE
[TROUBLESHOOTING HINTS] (1) Air/fuel mixture too rich — Insufficient fuel injection control (correction for coolant temperature); Fuel injector fuel leakage. (2) Vapor lock — Fuel pressure is not held in fuel line after engine stopped; Pressure regulator control system malfunction.
CRANKS NORMALLY BUT WILL NOT START (PARTIAL COMBUSTION) — AFTER WARM-UP (steps 1-4)
1
STEP 1: Warm up engine to normal operating temperature and stop it. Connect data link connector terminals F/P and GND by using jumper wire for 3 minutes with ignition switch ON. Does engine start?
Yes
Change to another brand of fuel
No — Go to next step
2
STEP 2: Remove vacuum hose from pressure regulator and plug it; Does engine start?
Yes
Check pressure regulator control system (page F2-120)
No — Go to next step
3
STEP 3: Connect data link connector terminals F/P and GND with jumper wire; is fuel line pressure correct by using ignition switch ON? (page F2-107). Fuel line pressure: 260—310 kPa {2.6—3.2 kgf/cm2, 37—45 psi}
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 fuel line and filter for clogging; if hose is not clogged, check fuel pump maximum pressure (page F2-110). High pressure: Is fuel return hose clogged or restricted? (page F2-115) If it is not, replace pressure regulator. If it is, repair or replace it.
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 fuel line and filter for clogging; if hose is not clogged, check fuel pump maximum pressure (page F2-110). High pressure: Is fuel return hose clogged or restricted? (page F2-115) If it is not, replace pressure regulator. If it is, repair or replace it.
Yes — Go to next step
4
STEP 4: In the same condition as step 2, is 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.