punto idle speed and judder

[andyhughes1199]

Hi
I have a fiat punto 1.2 8v on a 05 plate. It has done 23000 miles.
sometimes when on idle the revs are at 800 then suddenly drop to around 500 and keeps doing it. When driving especially accelerating it judders feels like its running on 3. It only does this at random. I have had it checked at a garage they put it on a diagnostic machine but found no problems, i was advised to have the coils changed which were done today, but the problem remains.
Any help to fix this problem would be greatly recieved, this car is my driving school car so i need to solve this problem asap
Andy

 

[wotan]

Check / change air filter if necessary, check & clean mass airflow meter.
Check for damaged split hoses connected to inlet manifold.

Wotan

 

[jonnyfishing]

You could try a new set of plugs and H/T leads.

 

[andyhughes1199]

i have cleaned the air filter it seemed fine , i dont think this car has a mass airflow meter. The hoses seem ok too, i will try changing plugs and HT leads tomorrow, fingers crossed that that fixes it
Thanks
Andy

 

[andyhughes1199]

Hi
I have changed plugs and HT leads, although running better now problem still remains. Would resetting the ECU help ? if i take off the battery cables for awhile ( how long ) ? and if i do that will i lose my radio code and central locking ?
Andy