2014 Aygo Cranks won't start

[jimshoe]

I have 1 2014 Aygo that is used only occasionally.

I tried starting it a few days ago and it turned over weakly but wouldn't start.  Mindful the Battery was pretty old I removed the old one and replaced it with a new Bosch one.

It will now crank strongly but refuses to start - no hint of firing.

I'm concerned that by having Battery out of the car for a few days I've screwed up the immobiliser i.e the car has 'forgotten' the key chip?

Of course it might be fuel and/or spark, but I'd like to eliminate the immobiliser (as cranking and not firing seems to be what the immobiliser would do).

Any ideas?

[flash22]

it has the correct Battery on it and the polarity is correct ??

Have you tried a spare key ?

[jimshoe]

Yes, polarity correct - I don't think it would crank otherwise?

Yes, also tried spare key - same problem.

D

[jimshoe]

Update (for anyone curious)

My problem turned out to be a siezed water pump which was preventing the alternator belt from turning.  A manual jiggle  got it free and then I replaced the water pump.  All fine now!