VAG reports multiple misfiring's error.......

[liviococcia]

Hello Members, i have a Polo 1.4 auto 2001 X reg( i don't know if it's MK3 or 4), and i try to do as much service and repair on it as i can, so i generally manage the standard easy stuff and anything i'm not sure about i look in the Haynes manual and consider if i'm confident enough to tackle it, and generally give it a go.

It has come to the point where it's time to do a service (Pads & shoes, air & oil filter, clean/replace sparks and/or leads, clean throttle housing), but i've been having a random problem, and my VAG handheld diagnostic computer is saying when the problem happens, it is a 'Random cylinder misfirings' , so i'm looking for any advice regarding any simple parts that might be worth replacing that may hit on a solution while i do this service.

The problem of the 'misfiring' tends to happen just after a sharp breaking event when driving, but has also happened when the car has just started up (a less common event though), the problem is also not an every day issue either, also, as the problem occurs the 'Rev-counter' flutters up and down dramatically.

The battery, or alternator has never been change, and i notice when lights are turned on, or the indicators are used, the engine's rythum will hunt in-sync of the indicators flashes, if the steering is being used at full locks the same is true especially when the car is stationary.

The 'Timing belts', thrust pulleys and 'Water pump' have been changed, this was done in 2005, the exhaust & cat has never been changed, but the O2 sensor number 1 was in 2008.

So basically i'm hoping members might have some guidence regarding what i should be looing at, to maybe sort the problem out .

Thanks for any help
reagrds
Livio

[Bepe]

if its multiple missfires, could possibly the Coilpack thats faulty, either that 2 or more HT leads or plugs have failed

[liviococcia]

Thanks for the help Bepe, i changed the leads a year and a half ago, including the plugs (all proper VAG parts, not compatibles), but i've never changed the 'Coilpack', i'm guessing this is just a straight swap of removing the old one, and replacing with the new one, is there anything else to consider that could reduce the chances of what could be causing the problems i'm having.

As you say i'll change the plugs again just to be safe, but not the leads, there expensive and i recon there least like to be the problem.

regards

[Bepe]

If you changed the Leads and Plugs over a year and a half ago then there due as your supposed to do them every year really, but yeah the coilpack could be faulty, its and easy change, but i would first of all change the plugs as its a cheaper option if it was just the plugs

[mwbpsx]

i had similar on a mk1 escort years ago. turned out the engine earth strap was snapped and the engine was using any earth available

[liviococcia]

Hello members, just to let you know, it did turn out to be one side of the coil pack.

What happend was i'd eventually broke down (not quite, but the engine check light came on, and the engine was really hunting), and called the AA, he diagnosed the fault (which was already pointed out to me on the forum as being a possibility), just by chance, where i had broken down right opposite me was a motor spares shop, so i bought a compatible replacement, the AA engineer fitted it........and as they say!.. the rest is history.

Thanks for all the help though, regards to you all
Livio