Toyota Corolla Startup Problem

[schakil]

The car is Toyota Corolla Altis 1.8 M/T 2009. On cold start in the morning, it is half self start. But later in the day, when warm, it cranks for 4-5 seconds, starts and then seem like it's stalling then rev back up to normal idle. Feels like injector are blowing fumes instead of petrol for the first few seconds. There is no other problem and it has great pick and very responsive. There is no miss firing, codes or lights

Things done so far:
1. Changed plugs.
2. Changed complete fuel pump assembly (fuel filter, fuel pump and pressure regulator) on advise of Toyota 3s.
3. Took it to another mechanic who said there is nothing wrong with injectors/fuel pump and problem is with wiring/electrics/sensor.

What is bothering me the most is that when engine is warm, it is quite obvious that fuel injectors are not throwing correct amount of petrol at startup and fumes are building up in the fuel line. But Why this doesn't happen on cold start in the morning if pressure regulator is not regulating the pressure of the fuel.

Looking fwd for an expert advise.

[schakil]

May be I am thinking in the wrong direction and the mechanic is correct but I am not taking it to any workshop until I have some expert advice.

[haseeb.basharat]

Which oil you’re using in this engine?
Feels like a common problem of vvti.

[schakil]

10w-40 SN.

[haseeb.basharat]

Have you cleaned its throttle body?

[schakil]

Yes, cleaned the throttle, changed air filter, oil filter, plugs, Even cleaned the air intake manifold and replaced the gasket.

[haseeb.basharat]

Nothing’s wrong with fuel lines or intake system than.
For fuel lines, all you can do is to pour one fuel injector cleaner in full fuel tank, it will clean them: http://www.liqui-moly.com.pk/injection-cleaner
Please get its vvti checked, there might be some issue in vvti. Google your query as well, you will get more than enough data on this 1zzfe engine cold startup issues. Cold startup issues were quite common in this engine.

[schakil]

At exactly "3000rpm", the engine noise become heavier. No vibration or bubbling and car runs fine at any speed. Is it also due to bad vvti?

[schakil]

Thanks for the quick replies. Actually there are no cold startup issues at all. Car starts in a blink in the morning. It's only when engine is warm, that it takes 3-5 seconds to start.

[Moderator]

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[schakil]

Thanks. I will definitely try that. But as I mentioned in my first post, I have recently changed the complete fuel pump assembly on advice of Toyota 3s Thokar Niaz Beg. But that didn't solve the problem.

[haseeb.basharat]

Did you fit original/genuine fuel pump, with complete fuel assembly which includes filter as well?

[schakil]

Yes, complete fuel assembly with fuel filter/fuel pump. Even the screen filter too. The only thing I didn't replace is the fuel gauge.

[Moderator]

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[schakil]

Great suggestion.. I will check with my mechanic if he has the fuel pressure gauge, else will visit toyota 3s. By the way, do you think a leaky injector might be the culprit? And how to check if any injector is leaking?

[imrankhanmsb]

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[schakil]

155k on odo. Catalytic converter cleaned few months ago. Haven't facing any issues related to clogged cat converter.

@Moderator Turning key on/off five times before startup didn't helped. The 4-5 second delay and initial hiccups were still there.

[imrankhanmsb]

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[schakil]

Thanks a lot for the offer. Do you have fuel pressure tester gauge? I checked with couple of mechanics in my area and as expected, no one has one.

[imrankhanmsb]

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