Hyundai i20 starting bother

[DIYspanner]

2009 1.4 petrol PB G4FA

Wouldn't start this morning. Cranking but not firing.

Took a plug out to see if there was a spark when cranking. Sparking but plug was in a poor state so I put a new set in. Still not starting though.

Plugged the code reader in but no faults found. Did an erase anyway but obviously a fail. Then the engine tried to start, then died again. Plugged the code reader back in and again, no faults but did an Erase again. Engine tried to start again but then died again.

Did the code reader a third time and this time, the engine spluttered for a few seconds and then started. Test drove it and all is well.

Engine management light goes out when started.

Seems a sensor may be failing so any do Korean car experts know what sensors these cars have and which are more prone to failure?

thanks

 

[Burnerman]

I hope you don't mind me hazarding a guess here but I would guess that there is no spark permanently there due to the crankshaft and camshaft sensors being out of phase......possibly due to the timing chain just starting to stretch. The sensors do come into phase at some point and then the engine is running fine - until the next start, maybe.
Unfortunately these don't always put the engine management lamp on, which is a huge bind.
Can you hear any timing chain rattle at all? These engines are rustle quiet, usually.
You could spend money needlessly here - any answers from the internet or somewhere?
John

 

[DIYspanner]

Thanks for the input John.

The car's been driven about 30 miles since I got it started with about 4 start/stops and all seems well.

Can't say I noticed any chain clatter.

As I mentioned above, no faults picked up by the ecu according to the code reader but will investigate the crank and cam sensor setup to see what its all about. I understand why the ecu needs a crank sensor for spark timing but I'm not familiar with cam sensors.

If it does happen again, then obviously it needs some attention.