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Home >> Isuzu >> 1997 >> Rodeo LS, 2.6 E >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Testing - 2.6L >> Trouble Shooting >> Engine Cranks But Will Not Run
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Engine Cranks But Will Not Run

WARNING: Relieve fuel pressure before connecting fuel pressure gauge. See FUEL SYSTEM PRESSURE RELEASE  under FUEL SYSTEM.
  1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  . After performing OBD system check, go to next step.
  2. Check IGNITION COIL fuse CB-4 (15-amp) and ENGINE DEVICE fuse CB-3 (15-amp) located in dash fuse box. Check PCM fuse EB-12 (15-amp) located in fuse/relay box in engine compartment. If any fuse is blown, go to next step. If fuses are okay, go to step 4).
  3. Check for short to ground in appropriate circuits. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. Replace any blown fuses.
  4. Turn ignition on. With a test light connected to ground, probe IGNITION COIL fuse CB-4 (15-amp) and ENGINE DEVICE fuse CB-3 (15-amp) located in dash fuse box and PCM fuse EB-12 (15-amp) located in fuse/relay box in engine compartment. If test light illuminates at all fuses, go to step 6). If test light does not illuminate at all fuses, go to next step.
  5. Repair open in appropriate ignition feed circuit. Retest system.
  6. Disconnect ignition coil to distributor secondary wire at distributor. Install spark tester at end of secondary wire. While cranking engine, check for crisp blue spark. If poor or no spark is found, go to next step. If spark is okay, go to step 23).
  7. Turn ignition off. Disconnect ignition module connector. Using a test light connected to battery voltage, probe terminal No. 3 (Blue wire) of ignition module connector while cranking engine. If test light flashes, go to step 16). If test light does not flash, go to next step.
  8. Check for open or short in Blue wire between ignition coil and ignition module. If Blue wire is okay, go to step 10). If problem is found in Blue wire, go to next step.
  9. Repair open or short in Blue wire as necessary. Retest system.
  10. Turn ignition on. Using DVOM, check for battery voltage at terminal No. 4 (Red/Green wire) of ignition module connector. If battery voltage is present, go to step 12). If battery voltage is not present, go to next step.
  11. Repair open in Red/Green wire or faulty ECM main relay. Retest system.
  12. Using a test light connected to battery voltage, verify module is being supplied ground at ignition module connector terminal No. 2 (Black wire). If test light does not illuminate, repair open Black wire. Retest system. If test light illuminates, go to next step.
  13. Check for open in Blue wire between PCM and ignition module connector terminal No. 3. Repair open circuit as necessary. Retest system. If circuit is okay, go to next step.
  14. Replace ignition module and retest system. If problem still exists, go to next step.
  15. Replace PCM. Verify system is operating properly.
  16. Turn ignition on. Ensure all coil connections are disconnected. Using a test light connected to ground, probe ignition feed circuit terminal No. 1 (Black/Orange wire) of ignition coil harness. If test light illuminates, go to step 18). If test light does not illuminate, go to next step.
  17. Repair open in Black/Orange wire between ignition coil and dash fuse box.
  18. Turn ignition off. Using DVOM, measure ignition coil primary resistance. If primary resistance is .8-18 ohms, go to step 20). If resistance is not as specified, go to next step.
  19. Replace ignition coil. Retest system.
  20. Measure ignition coil secondary resistance. If secondary resistance is 9000-12,000 ohms, go to step 21). If secondary resistance is not as specified, go to next step.
  21. Measure resistance of coil wire between ignition coil and distributor. If resistance is more than 22.5 ohms, go to next step. If resistance is 22.5 ohms or less, replace ignition coil. Retest system.
  22. Replace coil wire between ignition coil and distributor. Measure resistance of all plug wires and replace if any measure more than 22.5 ohms. Retest system. If problem still exists, replace ignition coil. Retest system.
  23. Reconnect coil wire. Disconnect one plug wire and install spark tester at spark plug wire. While cranking engine, check tester for crisp blue spark. If spark is okay, go to step 31). If poor or no spark is found, go to next step.
  24. Remove distributor cap and inspect for cracks, carbon tracking or other defects. If distributor cap is okay, go to step 26). If problem is found with distributor cap, go to next step.
  25. Replace distributor cap. Retest system.
  26. Inspect distributor rotor. If rotor is okay go to step 28). If rotor shows signs of excessive wear or damage, go to next step.
  27. Replace distributor rotor. Retest system.
  28. Disconnect wires from ignition coil. With distributor cap off, crank engine and inspect rotor. If rotor turns while engine is cranking, go to step 30). If rotor does not turn while engine is cranking, go to next step.
  29. Replace camshaft timing belt or defective distributor gear. Retest system.
  30. Using spark tester, test each untested spark plug wire. While cranking engine, check tester for crisp blue spark. If poor or no spark is found at any of 3 remaining plug wires, go to step 24). If spark is okay on 3 remaining plug wires, go to next step.
  31. Remove all spark plugs. Inspect spark plugs for fouling, loose or missing electrodes, or cracked plugs. Clean or replace spark plugs as necessary. If spark plugs are okay, go to next step.
  32. Turn ignition off. Install fuel pressure gauge to fuel supply line test fitting. Turn ignition on. If fuel pressure is 43-55 psi (2.9-3.9 kg/cm2 ) and holds steady, go to step 34). If fuel pressure is not 43-55 psi (2.9-3.9 kg/cm2 ) or does not hold steady, go to next step.
  33. If no fuel pressure is indicated, proceed to the FUEL SYSTEM DIAGNOSIS  tests. If any fuel pressure is indicated, proceed to FUEL SYSTEM ELECTRICAL TEST  .
  34. Install Injector Tester (J-39021) and switch box at injector test connector and activate fuel injector. If fuel pressure drops, go to next step. If fuel pressure does not drop, go to FUEL SYSTEM DIAGNOSIS  .
  35. Pressurize system with ignition on. Using injector switch box, test each injector for pressure drop. If a pressure drop exists for each injector, go to next step. If a pressure drop does not exist for each injector, go to FUEL SYSTEM DIAGNOSIS  .
  36. Remove Injector Tester (J-39021 ) and switch box. Connector Injector Test Light (J-39021-45 ) to injector test harness connector. Crank engine. If any tester lights blink while engine is cranking, go to step 42). If none of tester lights blink while engine is cranking, go to next step.
  37. Raise and support vehicle. Disconnect Crankshaft Position (CKP) sensor connector. Turn ignition on. Using a test light connected to ground, probe ignition feed circuit at CKP sensor harness terminal No. 1 (White/Orange wire). If test light does not illuminate, repair open White/Orange wire. Retest system. If test light illuminates, go to next step.
  38. Connect test light between ignition feed circuit at CKP sensor harness terminal No. 1 (White/Orange wire) and ground circuit terminal No. 3 (White wire). If test light does not illuminate, repair open White wire. Retest system. If test light illuminates, go to next step.
  39. Turn ignition off. Check signal circuit of CKP sensor between CKP sensor and ECM for open or short. If problem is found in CKP signal circuit, repair open or short as necessary. Retest system. If CKP signal circuit is okay, go to next step.
  40. Replace CKP sensor. Retest system. If problem still exists, go to next step.
  41. Test for fuel contamination. If fuel is not contaminated, go to next step. If fuel is contaminated, clean fuel system as necessary. Replace fuel filter and verify all fuel injectors are delivering fuel.
  42. Check for these possible conditions:
    • Faulty or incorrect camshaft timing belt.
    • Leaking or sticking valves or rings.
    • Leaking head gasket.
    • Excessive valve deposits.
    • Loose or worn rocker arms.
    • Weak valve springs.

    Repair as necessary. See appropriate ENGINE article in appropriate section. Retest system.

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