Hi,
I was experincing an engine light symbol displayed upon the dashboard whenever i went above 65mph. So i took it to Fiat dealership and the computer reported an Error - P0300, which is a ignition failure(generic), intermittent, with the danger of catalyser overheating.

Has anybody else experinced this problem and what caused it ?

The mechanic 90% belives its the HT leads, Was this the problem for anybody else who has had this problem ?

The car has just had a major service, with the cambelt, spark plugs, disc brakes and pads being replaced.

Thank you for your time and help

Tom

Ok the error is detected because the engine ecu sees a misfire due to the fact that the phonic wheel pattern has changed when the cam belt was changed. The phonic wheel is on the crankshaft pulley and is removed during the cam belt change, because it never goes back in EXACTLY the same place the pattern obtained by the rpm sensor does not match the one stored in the ecu, and at higher revs a misfire is incorrectly detected.

The car needs to go on examiner and have a reset of the engine ecu carried out and then a phonic wheel learn procedure carried out, this will cure the problem.

NumanR

Thanks Numan, that sounds alot more realistic then what the fiat mechanic told us. He said it was down to the new spark plugs fitted, not cambelt and he said that the HT leads needed replacing, as there werent working properly with the new spark plugs, although after saying that he said he was only 90% sure it would fix it, which made me begin to doubt him, as hes suppose to work with these cars day in day out !!!

NumanR said:

The car needs to go on examiner and have a reset of the engine ecu carried out and then a phonic wheel learn procedure carried out, this will cure the problem.

NumanR

Click to expand...

Hiya

Just to clarify, is this the same as, disconnect the negative terminal for 20 mins to clear the ECU, reconnect?

Having all sorts go wrong with my Punto this winter, shortly before I changed the wishbones, the RH side one gave way at the ball joint and I had a semi-dramatic crash at 25mph involving a bump off the kerb.

Everythings been refitted for a couple of weeks now but just noticed the P0300 tonight. Car has new plugs which I'm going to check. But also getting an O2 error which has been present for a while. Not noticing anything wrong with the engine running other than it's as flat as a fart, but only a 60bhp right?

Top this all off my battery has been going flat over the past couple of weekends and resetting the clock and electrics. My radio has also just popped (fluke?). I've just topped the battery up with distilled water today so see if that does the trick.

Any of these problems possibly related (O2 and P0300) I'm thinking even a flat battery could cause a misfire?

Can anyone tell me if a mk2 1.2 8v has a cat?

doubt the battery is at fault, however probs getting a new battery first wud be a good idea, the radio cud be a fuse *which* i think is F39 in the drivers fuse box check that first to see if that cud be the source of the problem and yes finally the 1.2 8v does have a cat and is 60Bhp

get new battery probably advisable, cud be the fuse the radio F39 iirc in the drivers fusebox and yes the 8v is 60bhp and has a cat.