Erratic Idling

Hi there, I own a 2004 Palio 1.6 and every now and again the car's idling goes all wrong, whether the car is cold or driven for 100km non-stop. The revs pick up to 3 000 rpm, starts misfiring and goes down again to 800 / 900 rpm, just to go up again. This cycle repeats no matter what I do, i.e. switching the car off and restarting (this used to help previously), tapping the petrol or driving the sh!t out of it. It does this every time I start the car now.

Had it checked by Fiat SA previously and they said it was the throttle body and replaced it under warranty (at least they said they did!). The problem disappered for a while and came back just after warranty period expired...

Not knowing feul injection or related electronic components, I don't even know where to start. Please help.

Thanks

Inside the throttle body there is a stepper motor which controls a plunger. The plunger has a rubber seal and due to dust the rubber seal tends to get stuck to the orifice which is the cause for your troubles. If you have the 1.6 sorry mate but you have no option other than cleaning the throttle body and hoping for the best or replacing it all together. If its the 1.2 engine then you can change parts individually. Bye and wear your seat belts.

Thanks for the advice. I stripped the whole induction system on the Palio up to a point where I could go no further (i.e. just before the fuel injectors as its covered by the air intake manifold) and gave everyhting a good dose of cleaning.

It seemed to have worked for now and the car even accelerates more smoothly through the grears. If the problem persists I'll buy a new throttle body (if I can find one!!!).

I am considering blocking off the oil/air breather system connected to the induction system and reconnecting the oil breather to a small air filter in order to keep the induction system (therefore the trhottle body as well) clean and free of oily substances (I hope I don't confuse the fuel injection with this).

I'll update this post with the results.