MB

Yep worth a try.

I've had the same before and it's been an injector (on another car) and once it was a lambda (overfuel)

Like I said, it's going to be tricky to diagnose without some tinkering.

Does it do it right from cold?

jimbob

Dodgy coil pack would throw a CEL?...It did on mine anyway.

teggboi

I have a similar issue, not really sure it's an issue but I get slight hiccups, shudders when idling after the car is up to temp. Thought maybe it has to do with how the motor is mounted, similar to how the car shakes when you turn it off. I'm also not getting any CELs and the motor has quite a bit of power, but the little shudders are making me paranoid so I'm going to change it out and test.

unclefester

I would clean out your IACV if i was you.

BenRNBP

The F20C can run very smoothly, taken me a good lot of fettling to get mine right; clean IACV and throttle butterfly, clean injectors,spark plugs - check the gaps as they often are a little off out the box - 1.1mm, and valve clearances are all good places to start. Grab a bluetooth ODB2 code reader and Torque app and have a look at the long and short term fuel trims too - they can tell you if the ECU is struggling to get the right air/fuel ratio ( short term fuel trim should be under 10% in either direction )

nomadicS2k

I can't get mine quite perfect at the moment, Got a 2nd hand set of coilpacks, new spark plugs, 2nd map sensor, used injector cleaner, done the IACV and the throttle butterfly. Next on the hit list are the o2 sensors which are non standard, but they were new blueprint ones I believe. It shudders a little bit, not massively noticable but it is there. I have some serious hesitation issues sporadically, seems to have been bought on by the warm (20C+) weather. I have an AEM v2, no heat shield material applied yet..

BenRNBP

Then, there's my favourite - The Italian Tune-up Took my wife's MK6 2.0 Turbo Golf to its service on Monday, I may have, ahem, "cleared some of the carbon out" as when I gave it back she said it felt more responsive all round and the idle sounded much better

The only injector cleaner that's worked for me is Redline SI-1 but even then, it's nothing like pulling them out and flushing carb cleaner through them after an ultrasonic bath in the jewelry cleaner.

MB

I had mega bad hesitaiton on mine - new primary O2 sensor (genuine) and it drives perfectly now. Amazing difference (I always advise changing these regualary)

nomadicS2k

MB - remind me where you got yours from- was it across the pond? I found them for $240 each.

BenRNBP

Not sure if this link will work but Rock Auto have the Denso ones for £68 +shipping and duty and NTK for £112 http://www.rockauto.com/en/catalog/h...2)+sensor,5132