Technical Low speed misfire

[Neil Barker]

My 54 plate Abarth seems to have developed an occasional low-speed misfire.

It's fairly precise and can be replicated - drive along and accelerate with full throttle from about 1500 rpm in say 2nd/3rd gear and at about 1700-2000 rpm, it will just shudder once and then carry on accelerating as though it's just misfired very briefly. I do not notice any other misfire at any other speeds.

At the moment, it's more annoying than anything else, but I'd like to get it sorted whilst the car is still under warranty....

Is this a sign of impending coil pack problems ?

 

[Deckchair5]

Could well be coil or plugs. Check your plugs first as a large gap makes the coil work harder, work means heat, overheat means more plastic insulator is more likely to fail

 

[Mr Wild]

Neil did you ever find the solution to your misfire as I'm having the exact same symptoms?

I doubt it is plugs/leads or packs as there's no problems once you're past 2000 rpm, it's just when under heavy load between 1500-2000.

Car seems flat as a fart generally though.

 

[Mr Wild]

Alright thought I would just say it appears this ones been solved.

I had some brand new (3 months old max) Bosch Super Spark 4's and some Bosch HT's, took the plugs out and the electrodes are all sooted up and black.

Swapped my old NGK V-groove's back in and its never misfired once, touch wood.

Pretty disappointed considering the cost of the Spark 4's, I wouldn't actually recommend them since it was only after I bought them I realised it doesn't actually use all 4 electrodes when it's firing, just uses the one of least resistance. Personally I'd probably advise going for the Bosch Super+'s or NGK Iridiums if you're so inclined since the Spark 4's seem to be a bit gimmicky to me.