Yaris occasionally won't start

[Toyoda]

Hi all, grateful for any advice..

Car is a 2003 1.0 petrol Yaris. So far, the car will always start from cold OK, however occasionally it won't start again after it's been driven somewhere and left say for anywhere between 5 minutes or a couple of hours. When it won't start, what happens is it cranks once then just dies. If you try it again it does the same, just turns over once, fails to catch then dies. As above, it's intermittent and the length of the journey leading up to it makes no difference.

When it fails to start, you either have to leave it a while and try again or sometimes an occasional pump of throttle starts it (but maybe that's just coincidence). I've had a similar problem on previous cars, but usually they keep on cranking but fail to start. With this one it's strange that turning the key just results in a single crank then nothing.

[Alpha Omega]

You are playing a guessing game unless you use a voltmeter on the circuit when the fault is on the vehicle

Measure between main positive and earth at the starter motor and then measure between the crank wire and earth, the fault must be on the vehicle when you are measuring

[GreenV8S]

Toyoda said:

what happens is it cranks once then just dies

When you say it dies, do you mean you're still holding the key in the 'cranking' position but it stops cranking?

[Bennachie]

Corroded earth strap junction under the battery...........

[Bennachie]

Corroded earth strap junction under the battery...........

[Toyoda]

GreenV8S said:

When you say it dies, do you mean you're still holding the key in the 'cranking' position but it stops cranking?

Yes, exactly that.