VW Polo 2013 1.2 TSI Missfire on warm up setting codes

[mdlamber]

Car: 2013 VW polo 1.2 TSI BlueMotion EA111 R4
Reoccurring problem of car going into limp mode, multiple codes stored relating to misfire.
Has had HT leads, spark plugs, battery, and most recently a fuel pump replacement at Continental Newmarket.
Symptoms have reappeared since then.
Customer says Dash lights come on when parked on a slope, car does not provide enough power to take off.
Switching from BlueMotion to Sports mode and idling for a few mins enables car to drive correctly.
Limp mode has also activated while car is being driven up a steep driveway, this occurs even after a long drive and has resulted in dangerous conditions for the driver.
Issue is intermittent.
When vehicle has been worked on by us the misfire is felt when cold and once the car is warmed up it runs faultless.
We have got it once to fault fully and go into limp mode where the cylinders detected we are guessing are cut permanently to protect CAT.
It was started and after 20 secs driven down a flat driveway and onto the road, once on road it went into limp mode.
Codes stored are P30100/300/400/200 P030000 P130A00

So every cold start will record misfires and will disappear after 3-5 minutes of running.
These are not just one cylinder and will vary from start to start, the Data stream does show number three cylinder with the highest count.
A decision was made to replace the Ignition coil module after some testing but the misfire fault still remains ( 2 road tests since coil done and no DTC )
Has anyone had much experience with this motor at all?
Fuel trims seem ok , but not available first thing on warm up.
Bore scope of direct injector area appears ok at this stage, no wet cylinder or leaking injectors. There is moderate carbon build up on the back of the intake valves.

Ive have taken multiple Pico scope samples using a 4425 model but they wont attach due to size.

looking for some advice on this issue please to have a good diagnostic plan moving forward (only info i have at this stage is Google)
It is a model I’ve had very little experience on,

Next steps
im looking at is checking valve timing ( chains are known to have issues) , although scoping of Cam v crank doesn't show movement.
Direct injector testing
Checking Carbon build up on valves.


Regards

Malcolm lambert
North Shore Toyota
Auckland
New Zealand

[liviu2004]

Have you seen Diagnose Dan video on vw tsi same issue video?

[ronw38]

Good video that one all of his are very informative. Usually multiple cyl misfires are a result of lean mixtures by air by passing the MAF like pcv valve sticking, brake booster leak etc anything that upsets air to fuel ratio, for starters I would scope the spark firing line on a couple of accessible cylinders longer time base and high sample rate 5ms and zoom to see if it confirms a lean mix with the spark not completing the burn and probably hook to the rail pressure at the same time Cheers Ron W Rotorua

[ronw38]

I should add the front 02 sensor, wide band could be scoped to confirm mixture live data, it should respond where as scan data can be locked out until parameters are met there is a simple hook up for Bosch wide-band on Pico training can send the link if you need Cheers Ron W

[mdlamber]

Hi Ronw38
Thanks very much for your input here.
Yes that video makes a lot of sense and
I have Picoscope files from what I have tested so far and definitely think its a lean misfire when its in a stratified warm up. When the High pressure pump changes tone after a few minutes of cold running warm up it I believe has changed from stratified to Homongeneous mode. Then the misfire vastly improves.

I do not have info for timing marks for the chain on this model but I do not see Cam vs Crank moving around too much (but do not know if it is correct)

have checked for vaccum leaks but it seems perfect when hot and fuel trims look good

Below is a download link off a website called WeTransfer of 3 pico files (too large for attaching)

https://we.tl/t-YueBKybjGm

kind Regards

Malcolm

[ronw38]

Thanks to Liviu for the video reference of DD, I downloaded your first capture of cam/crank, ignition, injection etc then it got difficult to display the rest, from that I see what looks like a lean misfire, [why?] Forget cam/crank/timing issues I recall seeing a post of a known good online recently and from memory matches yours plus you have no relevant codes. I would focus on ignition, injector amperage, rail pressure. I have said it before " its hard to fix a problem by correspondence" We are roughly in the same area if it helps contact me via Pico PM Cheers Ron W

[Fat Freddy]

There is moderate carbon build up on the back of the intake valves.

This, below, is on a FSI engine and was enough to cause the same symptoms. It's apparently a fairly common problem.

Not one I often see as I'm in Oz. I only went down that road after everybody else had played parts darts and from experience from when I worked in Auckland, North Shore (Forrest Hill). There we would often get misfiring Mitsubushi GDI's which were rectified after inlet manifold cleaning.
I used oven cleaner and dental tools to remove the carbon.

[mdlamber]

Hi there, thanks for the help.
We have carried out inlet manifold removal and soaked each inlet valve with strong cleaner and mangaged to remove a large portion of the carbon on the valves. The valves were not heavily carboned but enough there to want to do something about it.
Pre and post inlet valve clean we ran a Wurth cleaner product ( LBW400 ) through the injection system as well.
Id say after all of that pretty much 90 percent improved . No misfire or rough running felt on warm up. With scan tool a very small amount of misfire counts was seen but went away pretty quickly.
Customer will revisit for a recheck in a week but the signs are good.
If money wasn't an issue I would have done an injector removal and inspection as well as using a walnut blaster type system (which we don't have).

Thannks for the help

Malcolm