Strange misfire issue when cold

[DanGB]

Hello Chaps! 

Have a APR stage 3 car, Been having an issue, it appeared last year for a while, but went away, and now its appeared again for the last few months.

Basically, when the car is completely cold ie; when going to work in the morning, (not going home from work in the evening) it misfires on most or all cylinders on low revs until the car has reached 90c or just after that.

It doesnt bring up a CEL or Fault code, but can see it happening with VAG-COM on each cylinder, and can certainly feel it stuttering alot of the time.

Ive changed all coils and plugs, no difference. Intake flap motor was changed by my tuner a year ago.

APR have basically said go to VW[SEAT] and get them to fix it, but thats not an option because its out of warranty and they'd just blame all the modifications as per usual.

Im at a bit of a loss with this what to do now. Would be grateful for suggestions or help.

[bacillus]

This may be of some help even though you don't have a stored fault code


Technical Service Bulletin Transaction No.: 2017063/2
01-08-04 - MIL ON, Misfire DTC P0301, P0302, P0303 or P0304 Stored in ECM Fault Memory after Cold Start Release date: Oct 9, 2008

Condition

01 08 04 Jan. 23, 2008 2017063

MIL ON, Misfire DTC P0301, P0302, P0303 or P0304 Stored in ECM fault Memory after Cold Start

At times engine may run slightly rough for a few seconds after cold start. MIL may illuminate with a DTC for misfire on one cylinder only (P0301, P0302, P0303, P0304) stored in the ECM fault memory. Rough running condition disappears a few seconds after cold start and DOES NOT exist with a warm engine.

Technical Background

Not applicable.

Production Solution

Not applicable.

Service

1. Follow normal Guided Fault Finding Diagnosis, for example:

• Swap spark plugs and ignition coils between affected cylinder(s) and good cylinder(s).

• Check compression and leak-down of affected cylinder(s).

• Verify fuel quality. (Also refer to Technical Bulletin 2014815 - Gasoline Quality.)

• Swap fuel injectors between affected cylinder(s) and good cylinder(s).



Note:

When swapping fuel injectors, always replace all fuel injector seals.


2. If diagnosis results are inconclusive, and above mentioned condition persists, replace all 8 Hydraulic lash adjuster (lifters) of affected exhaust side.

Warranty

Information Only.

Required Parts and Tools

For Part No. reference, see table below:


Part Number
Part Description
Quantity

022 109 423 D
Hydraulic lash adjuster
8 (if needed)


06F 103 483 D
Valve Cover Gasket
1 (if needed)

06D 998 907
Sealing Kit for Fuel Injectors
1 (if needed)

[Poverty]

the VAG's strike again aye?

No use taking it to SEAT mate cause they wont have a clue, they cant even fix things when theres tons of fault codes all relating to the same thing 

Could try APS, or our local audi dealer though.

Best of luck, PS the noise seems to have disappeared from my car.

[DanGB]

Thanks Bacillus, I dont think its that, but will look into that further.

Who do you mean by APS Jase?

[john_o]

does it do it in stock mode Dan?

[DanGB]

Will try that john! (bearing in mind Stage 3 is the big turbo kit etc)