Hi all,

Where do i start, i have brought a 2004 (04 plate) Fiat Punto active and since i have had it, every now and then it rev's by itself, it doesnt do it all the time, but mainly when i first turn the car on (once it comes off the choke) and sometimes at junctions when i stop, but as soon as i put my foot on the accelerator it stops, may come back abit later, the car doesnt do it once its been driven for a while.

Now i have had a diagnostic done on it and the error code was P0300 (ignition failure), the machanic wasnt sure and sods law it didnt do it the whole time it was with him, he suggested changing Coil packs (done) and Sparks (done) and its still doing it, my brother has check the air filter and done a semi good clean of the throttle body... but totally runing out of ideas what it is, its so frustrating as it doesnt do it all the time for a garage to here it, it revs between 500 and 1500 RPM, the car sounds like its going to cut out but then the computer kicks in to stop it (causing the revving noise)

Thats the first problem, but im not sure if its related but its now sometimes kangerooing along when im in 2nd gear doing speeds of 20mph ish, this is mainly when its cold making me think it may be the choke thats out?

If anyone could shine any light on this it would be much appreciated as FIAT just dont want to help or admit its a common fault

thanks so much

what about ht leads?

SamuraiDragon said:

what about ht leads?

Click to expand...

That was going to be my next option, but surely leads wouldnt cause this? Was wondering if anyone else had suffered with a simular problem as apparently its very common, i test drove another Punto before i got this one and that did the exact same thing (why i didnt buy it) , i then test drove my one and it didnt do it until about 2 weeks after i got it, typical!

gabber987 said:

That was going to be my next option, but surely leads wouldnt cause this? Was wondering if anyone else had suffered with a simular problem as apparently its very common, i test drove another Punto before i got this one and that did the exact same thing (why i didnt buy it) , i then test drove my one and it didnt do it until about 2 weeks after i got it, typical!

Click to expand...

why not? if there is a break or faulty connection in one or more of them then the plugs cant spark etc. ht's are a common reason for missfires.

could also be a faulty throttle position sensor.

Try to read this (specially red-font):

Common Problems That Trigger theP0300

• Worn out spark plugs, ignition wires, coil(s),
• Incorrect ignition timing - think its not!
• Vacuum leak(s)- Check all rubber hoses comming into TB
• Low or weak fuel pressure - worth to check!
• Improperly functioning EGR system
• Defective Mass Air Flow Sensor-MAP (AIT sensor could be problem too, and its usually integrated together with MAP sensor)
• Defective Crankshaft and/or Camshaft Sensor- worth to check!
• Defective Throttle Position Sensor (hope its-not, because its integrated into TB and expensive too!)
• Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems - Think its NOT!

Link is:
http://repairpal.com/OBD-II-Code-P0300