I have a problem with my Abarth 2.4.
It sometimes won't start. When i push the start button, i can hear the gassoline pump working, but just no start or something at all. Just not another sound. No engine, no eletro motor no nothing. The battery is quite used for some years, it's not in her best shape. Allthought the car doesen't start, the windows work, every electrical thing works, so i don't think that this is it.
On the tester, nothing appears. The car seems to be perfectly fine.
Today i cleaned the fuses when it let me down again, and it started immediatly.
I think that this was only a fluke.
Any ideas?

Best regards.

You have push button start? Bypass the button and see if that cures it when it's being reluctant to do anything

Put a voltmeter across the battery and when you push to start see if the voltage drops dramatically and if you hear the starter solenoid click. If you hear a click but engine does not turn and nothing changes on the voltmeter then there is a problem with the starter circuit which is battery > starter solenoid>starter> earth.

If there is no starter solenoid click then there's problem with the push button to starter solenoid circuit