fiat punto misfiring and dropping power

[TGA]

Can anyone help me with the following problem, i have a 2002 1.2 8 valve fiat punto which has an intermittant fault whereby it goes from running perfectly fine to misfiring and dropping power. It has already had the ecu, coil packs, ht leads and spark plugs changed and it is no better! Any suggestions would be appreciated, thanks.

 

[^neo^]

What diagnostics has it had done on it already?

 

[Nitronick]

Keep it simple.

Add a lubricating additive to fuel and run it through. You may have a sticking valve or a blocked injector.

Cost less then a Tenner from Halford's

 

[gregers]

a friends g/friend had a simular problem with hers,and had various garages look at it,with a think were change the ecu to see if this will work attitude.
went to another and it turned out to be a cracked spark plug,dunno if this is causing your problems but start with the easy stuff 1st.

 

[wrinx]

Does the bad running coincide with anything or have a pattern...perhaps getting up to temperature or a hot engine?

Steve