Technical Abarth idle issue

[Luca74]

Good Morning

Hoping someone might have an easy fix for this.

A few weeks a go my abarth struggled to start. It would just keep trying to turn over but not actually start. I’d take the key out, put it back in and try again and it would always start up first time on the second attempt.
Sometimes i wouldn’t have the issue first go, but usually once a day i would and i start it 5/6 times a day.
Once, i started it and the revs just struggled to level off at the idle, and it spluttered and cut out.
It seems to be starting fine first time every time now, but when idling its constantly dipping as if its going to cut out, but never actually has cut out again.
It’s only done 20,000 miles, has a full fiat service history, and to try and fix this I carried out a full service recently with all genuine parts and abarth oil. Stuck in 4 new spark plugs, good ones (£££). However it still idles rough like it’s gonna cut out.
I only ever use premium unleaded. Anyone have any idea.
Many thanks

 

[ZaphodB]

A coil pack misbehaving perhaps?

You'd need to get diagnostics connected to see what errors there are..

In the absence of diagnostics you could try disconnecting the coil packs one by one (in turn then reconnecting) to see if the idle stays the same or gets worse.

If it stays the same as you disconnect one you've found the offending cylinder, if it gets worse (or stalls) it wasn't that one.

 

[Luca74]

A coil pack misbehaving perhaps?

You'd need to get diagnostics connected to see what errors there are..

In the absence of diagnostics you could try disconnecting the coil packs one by one (in turn then reconnecting) to see if the idle stays the same or gets worse.

If it stays the same as you disconnect one you've found the offending cylinder, if it gets worse (or stalls) it wasn't that one.

when I hooked it up to switch the service light off this was on there but it cleared down. The car was stolen when new in 2017 and repaired by Fiat.

 

[ZaphodB]

Double check the key battery is good, or just replace, that fault code would stop the car running, not make it idle poorly.

The no-start could be the key, or the receiver behind the barrel, or some damaged wiring perhaps (especially since it was stolen and repaired, who knows what they did there, did they give you paperwork when they repaired it?)

For now , check the coil packs for the rough idle.

(and just spell out what you consider a full service to see what you replaced)

 

[Luca74]

Double check the key battery is good, or just replace, that fault code would stop the car running, not make it idle poorly.

The no-start could be the key, or the receiver behind the barrel, or some damaged wiring perhaps (especially since it was stolen and repaired, who knows what they did there, did they give you paperwork when they repaired it?)

For now , check the coil packs for the rough idle.

(and just spell out what you consider a full service to see what you replaced)

I’ll change the key battery. Mechanic at work said could be a faulty earth cable, specifically the one that mounts on the gearbox.

Well, not sure if technically correct to call a full service, but I changed oil and cabin filters. Renewed oil with abarth selenia, renewed spark plugs, actually installed a ram air induction kit because this car makes me feel young again. Checked all other fluid levels etc.