General Help needed or advice on 55 plate punto dynamic

[tracyru]

hi, new to this site but need help please - i have a 55 plate fiat punto dynamic 1.2, on wet damp mornings straight after starting up it starts juddering and sounding like possible slight misfire randomly and fluctuates between 1100rpm and 900rpm. when trying to drive it when doing this it struggles to get to 2500rpm but after that power kicks and the car goes (the only way i can explain is if you are sitting on a fair ride when it kicks in and you get that boost of power - once the car is warm all this disappears and runs fine.
Has been taken to garage who cant find any faults with it and amazingly doesnt do this when they drive it.
I do have a video with the noise sound of this happening.

 

[oldhammer]

hi,

it couid be the HT leads are 'Aged.

spray them with something 'like wd40, then if the problem goes,

replace them, theyre fairly..cheap at euro car parts,

 

[Brendan W]

I would agree with oldhammer's comment. By the time you get it to a garage the leads have dried out. I'm still on original ht leads at 114k. If dirt is allowed to build up on the leads it can act like a sponge for moisture. It's good practice to wipe them clean every so often and fire the odd dose of WD-40 at them from plugs to coils. This is the job WD-40 was made for.

 

[tracyru]

thanks guys will give it a go and hopefully will help sort out the problems

 

[Brendan W]

Another useful trick is to remove the air filter and run the car in the dark. Any weakness in the ht lead insulation will show up as sparks escaping to the handiest earth point. Typically you'll see it between the leads and the block.

 

[Ziggy122]

This is how my HT's were arcing out

its a prominant noise - the camera didnt seem to say the same
But you can see the tiny flash's occouring

Driving it - it was horrible, as sometimes it'd arc - sometimes it wouldnt

They were 2months old before i got them replaced

Ziggy