This is a 2008 Toyota Vitz.

Neither I nor the mechanics I've been to can figure out what’s wrong with my car.

Every time I go to a mechanic they tell me a different story and ask me to change different parts. When I start it in the morning or after a few hours it takes time to start. I can hear it struggling and sometimes it starts on second or third try.

I’ve been to three mechanics and each told me different story and made me replace different parts (plugs and injectors).

I've asked them to check the airflow sensor they said it's fine.

Here's a video of the problem.

If anyone can tell me what I should ask my mechanic to look for, or if anyone has fixed a similar problem that would be really helpful.

Thank you in advance.

  • What’s the fuel pressure when it doesn’t start? Replacing pumps on toyotas is pretty rare but the regulator could be bad.
    – Ben
    Feb 23 '18 at 12:03

The symptom is explained by low pressure in the fuel rail.

If this was happening only during hot starts I would investigate the following, since in fuel-injected systems, hot-start problems indicate that the fuel line is unable to maintain pressure:

  • a leaky fuel injector
  • cracks in the fuel line which leak fuel when under pressure
  • a bad non-return valve in the fuel line which is allowing pressurized fuel to flow backwards

The reason why this happens only for hot starts is because the fuel is more likely to vaporize as temperature increases. In order to avoid vaporization problems the fuel lines are expected to be pressurized during a hot start.

However, since you mention that this also happens in the morning (cold-starting)there is something else going on here, fuel rail pressure is severely low, so I would check for the following as well:

  • a clogged fuel filter
  • a faulty fuel pressure regulator
  • 1
    The mechanic should put a fuel pressure tester on the car to ensure this is the problem, though to me sounds completely right. Feb 23 '18 at 14:02
  • zaid, I did change the fuel filter and asked the mechanic to check the pump which was working fine, then he checked for fuel leakage, and after that he checked fuel and oxygen intakes (injectors) which were working fine. I've 80000km on this car and the mechanic said it's normal this happens to most of the vitz and no once can solve it, I even asked hi if it's a faulty part I'm willing to replace it but no one seems to know what the problem is. I'll take it again tomorrow for a full scan Ill ask then to replace the fuel pump and check for problem there.
    – Usman
    Feb 24 '18 at 15:55
  • 1
    My recommendation is to go to a mechanic who can read fuel rail pressure with a gauge. Don't throw new parts at the problem in the hope of a fix.
    – Zaid
    Feb 24 '18 at 16:19
  • I did that today and all of three fuel injectors were leaking because of which the fuel pressure was dropping, thank you again.
    – Usman
    Feb 25 '18 at 22:03

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