Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Hard Start
DEFINITION:Β
The engine cranks OK, but does not start for a long time. The engine eventually runs or may start and immediately die.Β
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Were the Important Preliminary Checks performed? | - | Go to Step 2. | Go to Symptom DiagnosisΒ . |
| 2 |
Do the ECT and the IAT readings differ from the ambient temperature by more than the value specified? |
3 Β°C (37.4 Β°F) | Go to Step 3. | Go to Step 4. |
| 3 |
Is the repair complete? |
- | System OK | - |
| 4 |
Does the voltage measure within the value specified? |
0.4 - 0.8 V | Go to Step 5. | Go to Step 25. |
| 5 |
Is the repair complete? |
- | System OK | Go to Step 6. |
| 6 | Check the fuel pump operation. Does the fuel pump operate for the specified time when the ignition switch is turned ON? |
2 sec. | Go to Step 7. | Go to Fuel Pump Relay Circuit Check . |
| 7 | Check the fuel system pressure. Is the fuel pressure within the specifications? |
310 kPa (45 psi) | Go to Step 8. | Go to Step 26. |
| 8 | Check for water contamination in the fuel. Is fuel contaminated? |
- | Go to Step 9. | Go to Step 10. |
| 9 | Replace the contaminated fuel. Is the repair complete? |
- | System OK | - |
| 10 |
Does the test light blink at all connectors? |
- | Go to Step 13. | Go to Step 11. |
| 11 | Check the fuel injector driver wiring harness, the connectors and the connector terminals for the proper connections. Is the problem found? |
- | Go to Step 12. | Go to Step 27. |
| 12 | Repair the wiring harness, the connector or the connector terminal as needed. Is the repair complete? |
- | System OK | - |
| 13 | Measure the resistance of each fuel injector. Is the fuel injector resistance within the value specified (20 Β°C [68 Β°F] - the resistance will increase slightly at higher temperatures)? |
11.6 - 12.4 Ξ© | Go to Step 15. | Go to Step 14. |
| 14 | Replace any fuel injector with a resistance that is out of specifications. Is the repair complete? |
- | System OK | - |
| 15 | Perform an FUEL INJECTOR BALANCE TEST
. Is the problem found? |
- | Go to Step 16. | Go to Step 17. |
| 16 | Replace any restricted or leaking fuel injectors as needed. Is the repair complete? |
- | System OK | - |
| 17 |
Is the problem found? |
- | Go to Step 18. | Go to Step 19. |
| 18 | Correct or replace any faulty ignition components. Is the repair complete? |
- | System OK | - |
| 19 | Does the engine misfire or cut out under load or at idle? | - | Go to Ignition System Check | Go to Step 20. |
| 20 | Does the engine start, but then immediately stall? | - | Go to Step 21. | Go to Step 23. |
| 21 |
Is the problem found? |
- | Go to Step 22. | Go to Step 25. |
| 22 | Repair the faulty connections as needed. Is the repair complete? |
- | System OK | - |
| 23 |
Is the problem found? |
- | Go to Step 24. | Go to Step 25. |
| 24 | Repair or replace any components as needed. Is the repair complete? |
- | System OK | - |
| 25 | Check the throttle position sensor circuit for proper operation. Repair or replace components as needed. Is the repair complete? |
- | System OK | - |
| 26 | Repair the fuel system as needed. Is the repair complete? |
- | System OK | - |
| 27 | Replace the ECM. Is the repair complete? |
- | System OK | - |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
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