Toyota Yaris - Toyota hot starting problem - markweatherill

I wonder if anyone can help?

My car is a Toyota Will Vi, a Japanese import with Yaris mechanicals. It has the 2NZFE 1.3L VVTi engine.

When it's cold, it will start every time with a few churns of the starter.

When the engine is hot, eg I drive somewhere, leave it half an hour and come back, it almost invariably will not start first time. But turning the key back and trying again straight away, it almost always does start. Occasionally it won't and a third try is needed.

If I keep the starter going, it still won't start. It may splutter a bit but it's as if something, either the sparks or the fuel, is turned off and won't come back on until the second time of trying. At which point it merrily will start and run just like it should.

So far I have changed the MAF to no improvement, but now I think I need to start testing things.

What should I be looking at, please? This isn't a common problem with Yarises as far as I can tell.

Toyota Yaris - Toyota hot starting problem - madf

"When it's cold, it will start every time with a few churns of the starter."

Normally it should start straight away.

"

When the engine is hot, eg I drive somewhere, leave it half an hour and come back, it almost invariably will not start first time. But turning the key back and trying again straight away, it almost always does start. Occasionally it won't and a third try is needed.

If I keep the starter going, it still won't start. It may splutter a bit but it's as if something, either the sparks or the fuel, is turned off and won't come back on until the second time of trying. At which point it merrily will start and run just like it should."

You really need to test the engine when it is warm and has not started. Test for a spark first. You must have an intermittent heat related fault which sounds like a sensor is on the way out..

If there is no spark, 10:1 it's the crankshaft position sensor..

If there is a spark check you have fuel..If none, go from there.

You need a multimeter and wiring diagram to test.

Toyota Yaris - Toyota hot starting problem - markweatherill

Just to update:

This car, like many Toyotas, uses a 'circuit opening relay' to operate the fuel pump so that it's only working when a) the engine is cranking and b) when it's running.

Somehow the ECU wasn't turning the fuel pump on under hot start conditions. Checked by feeling the relay with my finger each time.

I thought it would help the car start better anyway to have the fuel pump come on with the ignition, so I've bypassed the circuit opening relay with a jumper wire.

The car starts every time now, hot or cold, nice and quick.

Toyota Yaris - Toyota hot starting problem - jc2

The relay(or similar) on the fuel pump is a very sensible legal requirement;it is there to switch off the pump if the engine is not rotating when the ignition is on.

Toyota Yaris - Toyota hot starting problem - Collos25

Sounds like a petrol fire waiting to happen if you ever have an accident and they discover what you have done the insurance company will disown you.

Toyota Yaris - Toyota hot starting problem - madf

Have you fused the wire? If not, you are an accident waiting to happen..

 

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