Hi all...first post

Just bought a 1.2 8v Punto for the daughter, its a november 03 with 72k.

It runs and sounds fine but on tick over when warm has a lumpy erratic idle. Ive changed the plugs (old plugs looked fine), new air filter and valves sound ok. Cant see any inlet leaks but need to check again.

Any pointers?

Lambda sensor may be dirty or need replacing

Clean the throttle body (TB) with carb cleaner and cotton buds - cheap to do but be careful to not leave any lint behind and dont damage any delicate parts. Its easiest if you take the TB off the car.

If its no better look at the lambda sensor. They tend to run ok when cold but go lumpy when hot and fuel consumption is poor.

Throttle body usually tends to affect it when cold then fine once warm

Mine does the rev up and down thing when first started but it's fine once running. I think the TB is telling me it needs cleaning. Clean plugs suggest its less likely to be the lambda.