Just had a quick read. Have you logged MAF? Gone for a drive with it unplugged? No air leaks?
 
Sorry to sound thick dan but how do I log MAF? (I know through VCDS but what am I looking for?)
And unplug it..go for quick drive & try & replicate fault..if it's gone it points to the MAF, if it's still there MAFS ok? Getting smoke test Friday for air leaks


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Another thing..parked up..car running..press throttle, hold at a steady 2000rpm & the revs will begin to rise & fall & fluctuate without moving throttle pedal!


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Sorry to sound thick dan but how do I log MAF? (I know through VCDS but what am I looking for?)
And unplug it..go for quick drive & try & replicate fault..if it's gone it points to the MAF, if it's still there MAFS ok? Getting smoke test Friday for air leaks


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Log block 002 g/s and boot car in 3rd gear from 2000 rpm to red line and tell us your maximum g/s
 
PCV changed with clutch couple month ago..DV changed like 2 days ago lol..

So how do I test the MAF? As I said a couple of posts above?

And cheers WeeG will do that Friday when it's at the garage! ('Roughly' what should I expect? Revo stg 2, MTC/ITG intake)


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PCV changed with clutch couple month ago..DV changed like 2 days ago lol..

So how do I test the MAF? As I said a couple of posts above?

And cheers WeeG will do that Friday when it's at the garage! ('Roughly' what should I expect? Revo stg 2, MTC/ITG intake)


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Sorry to bring up an old thread.
Did you ever get to the bottom of this, my cupra is doing the exact same thing, only misfiring on light throttle when cold.
When the car is warm it doesn’t seem to miss and runs fine.
Any help would be appreciated
 
Had the same issue with fluctuations, on both my cupra 2010 and on my m8s 2007. Replaced pcv with catch can after trying a 2nd pcv and to be honest best thing I've done solved the issue. On my m8s car it was the brake servo pipe had cracked causing a leak. Replaced and his issue went away however was doing the exact same revving, could also be a few other things but those two things are always good to check, brake servo pipe also cracked on mine so must be a common thing, I just taped mine haha
 
Had the same issue with fluctuations, on both my cupra 2010 and on my m8s 2007. Replaced pcv with catch can after trying a 2nd pcv and to be honest best thing I've done solved the issue. On my m8s car it was the brake servo pipe had cracked causing a leak. Replaced and his issue went away however was doing the exact same revving, could also be a few other things but those two things are always good to check, brake servo pipe also cracked on mine so must be a common thing, I just taped mine haha
Thanks for the reply, mines not really fluctuating it idles Ok just has I misfire on idle and at low revs and light throttle the car misses and hesitates. If you put your foot down it stops and drives normally, I’ve had it on a diagnostic where I work and it’s only missing on cylinder 3, I’ve also done plugs and coils as that’s what I thought the problem was.
 
Thanks for the reply, mines not really fluctuating it idles Ok just has I misfire on idle and at low revs and light throttle the car misses and hesitates. If you put your foot down it stops and drives normally, I’ve had it on a diagnostic where I work and it’s only missing on cylinder 3, I’ve also done plugs and coils as that’s what I thought the problem was.

Worth having the injectors removed, cleaned and tested?
 
Worth having the injectors removed, cleaned and tested?
I was thinking it pointed towards an injector as there’s no fault codes, you can only pick the misfire up on the counter when bringing up all the cylinders.
 
Thanks for the reply, mines not really fluctuating it idles Ok just has I misfire on idle and at low revs and light throttle the car misses and hesitates. If you put your foot down it stops and drives normally, I’ve had it on a diagnostic where I work and it’s only missing on cylinder 3, I’ve also done plugs and coils as that’s what I thought the problem was.

be interested in this thread as having exactly same problem - hesitation and huge back fires but no fault codes.

updates would be appreciated!
 
be interested in this thread as having exactly same problem - hesitation and huge back fires but no fault codes.

updates would be appreciated!
Hi Adam,

Just got rid of my mk2 unfortunatly, just got an S4 B9 haha I liked the mk2 but maybe it was just me being unlucky...I was always fixing it... I had this issue due to 2 reasons when I had it however, first time was due to an injector but didn't throw really any faults. 2nd time was due to the runner flap motor next to the intake manifold, wasn't opening fully so caused misfires, bad idle sometimes and intermittent hesitation a lot, never got an error code for that either..
 
Hi Adam,

Just got rid of my mk2 unfortunatly, just got an S4 B9 haha I liked the mk2 but maybe it was just me being unlucky...I was always fixing it... I had this issue due to 2 reasons when I had it however, first time was due to an injector but didn't throw really any faults. 2nd time was due to the runner flap motor next to the intake manifold, wasn't opening fully so caused misfires, bad idle sometimes and intermittent hesitation a lot, never got an error code for that either..
thanks for the info - i had a specialist look at it and diagnosed a possible ecu fault with regards to ignition. cant read the ecu either. ive got another ecu being de-immobilised and will give it a go.... cheers