Troubleshooting Guide — 17 Hesitates/Stumbles on Acceleration (continued)
F2-49flowchartStep 11 references the Variable Resonance Induction System (VRIS), which is specific to the K8-ZE V6 engine.
17 Hesitates/Stumbles on Acceleration (steps 7—12)
1
STEP 7: Is fuel line pressure correct at idle? (page F2-113) Fuel line pressure: 260—310 kPa {2.6—3.2 kgf/cm², 37—45 psi} (Vacuum hose to pressure regulator disconnected)
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 quickly acceleration? If it does, check fuel line and filter for clogging. If it does not, go to next step
3
STEP 8: Connect System Selector 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
4
Does ignition timing advance during acceleration? If it does, go to next step. If not, replace ECM (page F2-141)
5
STEP 9: Are air duct and air hoses correctly installed?
No
Repair
Yes
6
Go to next step
7
STEP 10: Is exhaust system restricted? (page F2-120)
Yes
Repair or replace
No
8
Go to next step
9
STEP 11: Is variable resonance induction system (VRIS) OK? (page F2-102)
No
same as step 7
Yes
10
Go to next step
STEP 12: Try a known good ECM and check if condition improves (page F2-141)