Couple of vRS queries...Update!

[LukeRs]

Probably me just worrying, but I'd like to ask your knowledge!

I'm having a couple of small issues with the vRS and curious to what they are.

1. Last few days I have been using it for work and over the weekend, I have noticed on first start up (I usually start it up, whilst I put laptop, lunch and jacket in the car) there is a bit of a petrol smell from exhaust, I can't recall smelling this until recently. Is this normal?

2. Very hesitant, jumpy and misfiring. 9/10 in a morning I get this, I know before I thought it was secondary air pump but I don't think this is. If you let off the throttle and let the car run - the revs are very jumpy and to the point it nearly cuts out as it goes too low. Sometimes you put foot to floor, revs don't go anywhere at all but others it does. I'd say sometimes it's jumpy when driving like you can feel it's not 100% right. This always corrects within 1-2mins.

Now, spark plugs were changed at Awesome on 6th August at bang on 38000 miles and now I am on 43,990 to be precise.

Any ideas?

Luke

[Oet]

coilpacks dude, also worth cleaning your throttle body out

i just had to buy a full set of coilpacks, as they tend to go quickly after one another (3 of 4 of mine have now gone), awesome sell sets of four for 95 posted, cheaper than main stealer at 335 a pop and they are genuine oe packs too.

[LukeRs]

Does it sound like coilpacks then obviously?

It's still covered under warranty until 29th of this month, will the machine pick it up?

[Oet]

well coilpacks can give some of those issues especially misfire, is the problem only on startup or is it anytime ( i think you are saying its anytime)?

[Oet]

yes a scan on diagnostics software will tell if its coilpacks or what the fault is

[LukeRs]

It's only on startup the misfire.

Although ever so slightly it's a bit jumpy in traffic when warm.

[Liverpool-Lad]

And under full power no hesitation?

[Oet]

def worth getting it scanned, and cleaning TB as suggested

[Oet]

also scan can check maf/n75 and sensors like o2

[LukeRs]

No hesitation after a few minutes or under full power.

TB was cleaned about May last year I think, but I guess could need doing again.

[Oet]

get it on vag.com

[LukeRs]

Might just send it straight to Skoda tbh.

Warranty is there until end of the month.

[Oet]

yes they will do it for you, esp if under warranty, its not right so worth getting it in now

[Bowders1]

As stated coilpacks could be the issue, but some of your symptoms could be down to a temp sensor.

As you have warranty get garage to check it out.

[LukeRs]

What about the petrol smell too?

[VRS Mike]

What about the petrol smell too?

if the coilpacks aren't firing then you will not be combusting the petrol in the cylinder so you will get a strong petrol smell from the exhaust. My first thoughts were TB but as this was done last year I doubt it's that. If you've got warranty then use that mate.

[Liverpool-Lad]

No hestitation at full power doesnt suggest coilpacks, but fault codes will help here more.

[Oet]

indeed, coilpacks usually degrade performance the whole time not just at startup so vag scan required to determine where and what it is.

[snow_muncher]

Coilpacks can breakdown in a manner which is not detectable to VAGCOM. I've pulled one out which was burnt in half, that vagcom didn't detect as faulty

I suspect VAGCOM checks a circuit inside the top of the coilpack, not whether any spark is being correctly generated

[stig1]

coolant temp sensor send it to skoda if you got waranty use it mate before it runs out

[VRS Mike]

can't vagcomm do a misfire count and detect on which cylinder there is a misfire?

[Oet]

yes thats what i thought too?

[snow_muncher]

This is ideally the type of thing VAGCOM should tell you:

VAG-COM Version: Release 311.2-N

Chassis Type: 1U - Skoda Octavia

Scan: 01,02,03,08,15,17,19,35,46,56

Address 01 -------------------------------------------------------

Controller: 06A 906 032 HJ

Component: 1.8L R4/5VT 0002

Coding: 10700

Shop #: WSC 78387

TMBSL21U828554744 SKZ7Z0A1187886

3 Faults Found:

17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)

P1297 - 35-10 - - - Intermittent

16684 - Random/Multiple Cylinder Misfire Detected

P0300 - 35-00 - -

16687 - Cylinder 3 Misfire Detected

P0303 - 35-00 - -

Readiness: 0000 0000

End -------------------------------------------------------

Replaced coilpack 3 (3rd from left), clear codes, rescan, all OK

But as said, sometimes vagcom seems unable to detect exactly which cyclinder is misfiring :wonder:

In this case the '16687' errorcode entry wasn't present.

[Oet]

apparently it uses crank sensor to help detect misfires

taken from vwvortex

step 1- misfire occurs, oxygen doesnt combine with fuel

step 2- oxygen then flies by the oxygen sensor

step 3- the ECM uses the crankshaft position sensor(engine speed) to detect crankshaft acceleration at each ignition pulse, correlated against the camshaft position sensor (engine position) it can be determined which cylinder is missing. this is also how the ECM can tell the difference between misfire and a lean condition. if crankshaft acceleration remains constant then more fuel is added and this is where the LT/ST fuel trim numbers start to change.

step 4- this is the step where the typical vortexer will start throwing parts in an attempt to fix said misfire.

[LukeRs]

car went in today and no faults could be found, i think that's a bit of bull to be honest.

not sure what to do...tempted to find someone to vagcom it myself.