2.0 FSI Poor idle when cold

[JustCruisn]

Are you using 19mm irrigation pipe for your PCV hoses ?

[saabman]

Are you using 19mm irrigation pipe for your PCV hoses ?

I was wondering if anyone would notice.

The pipe from crank case to rocker cover had totally disintegrated and the poly pipe was a nice fit - just needed to heat it up a little to stretch over the fittings, The PCV valve diaphragm had torn some time ago so to prevent excess crank vacuum I plug the manifold port and rerouted the rocker cover outlet to the air filter box. I wanted to go in between the air filter and the throttle body but that was no nice place to tap in. I havent measured the vacuum there yet but its better than nothing and wont be sufficient to cause damage to the seals.

The poly pipe goes a bit soft when it heats up but there is no significant vacuum or pressure on it to cause any problems. Its easy enough to go back to the correct configuration when i get my hands on the right parts. Being a BLX motor nothing seems to be readily available for it.

[saabman]

Ive cleaned the valves as best I can. The "ghetto" blaster and soda worked a treat.



taking photos down the intake path is some what difficult but now I have relatively clean valves.


Big tip if your going to try this

DO IT OUTSIDE

despite attempting to use a vacuum cleaner to suck up the stuff - it was not good enough and everything in my shed is now covered in Bicarb Soda

wear a mask and goggles -

a dust mask does NOT cut it - and you need googles that fit tight around your eyes.

[saabman]

As I worked my way through the cylinders my results got better.

I had a lot of gunk on the shaft of the valve just hitting it with the blaster wasnt sufficient so found I needed to scrap it off a fair bit first.

I tried sanding down a toothbrush but that wasn't really long enough - i ended up using a length of aluminum "braising" rod it was reasonable stiff to scrape the gunk off before hitting it with the soda.

To get the residual soda out I tipped a bit of petrol in and then blew it out with compressed air with a rag over the inlet to catch the spray.

A good compressor is a must you really pump some serious amounts of air in when doing this.

Ill log a cold start in the morning to see if it has made any difference. The start I did after cleaning did sound a bit better but I had had the battery disconnected for a couple of days so not sure of the status of fuel trim etc.

[saabman]

Ive just been looking at the logs and comparing a cold start this morning (after the clean ) to previous logs and the thing most interesting is manifold vacuum is markedly different (Ill post the graphs later when I can sit down with out the kids yelling) and the ignition timing from around 30deg ATDC to around 8deg ATDC. !!

What is really interesting is I did a log couple of weeks ago (Pre clean) and those figures are almost identical to todays. I only have access to this car when its playing up as my daughter lives a couple of hours away. So cant get regular logs.

what I have noticed is the idle hasnt been as bad this time around (before I did anything) and inspecting the valves (ill need to have a closer look at the photos I took earlier) they didnt appear as dirty as I recalled them to be. I did disconnect the crank case ventilation when I had it last so it has had 12 months + of no oil been fed into the intake manifold. Im wondering if by removing the source of oil from the valves the engine heat has softened and drawn of the oil/soot residue and effectively self cleaned.

[SameerKhan]

Hi,
Has anyone tried to resolve this through a inlet valve cleaner? like the CRC GDI Valve and Turbo cleaner?

[saabman]

Hi,
Has anyone tried to resolve this through a inlet valve cleaner? like the CRC GDI Valve and Turbo cleaner?

Very early in my investigations I looked into using something like seafoam but found too many reports where people tried it and then did a physical inspection and found no change.

I also tried soaking the valves in carby cleaner (close vales and fill up the intake with it) but that did nothing.

the soda blasting was the most effective and the messiest

Due to the design of the BLX engine it is very difficult to get to the valves due to the loaction of the fuel injectors preventing the easy removal of the flaps in the intake

[maro]

Hi, I have BLX in my Octavia II. Firstly please take my admiration for not giving up on this engine. I experienced some pain during battle with NOX sensor. Lack of info and discussion for non turbo FSI is frustrating.

I am currently experiencing some irritating hesitation on WOT. Armed with VCDS (and deepOBD) i have done dozens of hours of live logging testing every sensor that could cause this only to find out disturbed air flow is probably the culprit.

Yesterday i cleaned throttle body and smoked engine compartment which revealed nasty slipped CLIC clamp (have i mentioned i own pliers for these evil clamps but forgot to take the thing with me? HAHA)



Next i was planning to clean intake manifold and scrub valves to remove all the deposits.


I was hoping the injectors could stay put and only lower manifold with flaps and motor needs to be detached as decribed in workshop manual for BLX.

It basically says:

• disconnect fuel lines
  
• detach fuel pipes
  
• disconnect electric harnesses
  
• detach PCV breather hose
  
• unscrew screws pointed by arrows
  
• pull off lower intake

I was imagining it something like this with injectors still in place.


Workshop manual supports this theory having pulling off injectors as another chapter with lower manifold already out.


Please explain what is the issue here. Thanks

[saabman]

Yep having to pull the injectors out me off pretty quick-I guess it’s one of those things that once youve done it once it’s probably not that bad. As you can see from the photos I posted above I did the blasting with out removing the flaps and injectors though it would have been a better job - but it was sufficient.

In my daughters I never did any hard driving so WOT response I never looked at but never noticed any drivability issues. I’m wondering if you have a partially blocked cat limiting the flow at high throttle openings.

It’s been a while since I touched the car - though it’s usually about this tone of the year something goes wrong with it and brings it back to me

Did you rectify the NOX issue?

[maro]

It is strange, because it does not always hesitate. After cold start or 15 minutes rest after long run it is very responsive. Response gets worse when engine gets to the operating temperature. Fuel supply and HPFP is OK - 110 Bar immediately in rail whenever throttle is pressed. I can tell based on measuring block 39/1 intake air mass when it is going to hesitate (value slooowly raising to ~40g/s) and when it shreds road (value almost instantly jumps to ~60g/s).
Response noticeably improved after cleaning throttle body and fixing that vacuum leak but it is still under my expectations.

I even make test trip with O2 sensors (B1S1, B2S1), MAP, EGR valve, IAT, camshaft adjustment valve unplugged but engine behavior was the same Funny thing the intake air mass block still showed values. There is no MAF on BLX so it is computed somehow. I tried to find out from funktionsrahmen but the german is killing me.

I am planning to order cheap compression tester from aliexpress with O2 sensor plug to do backpressure testing. After all BLX has 4 cats in my case with 220 thousands kilometers on them so they may be collapsed or melted. But i hope it's all the gunk in the intake manifold on tumble flaps and valves that is causing this.

NOX issue is currently not resolved. OEM part is absurdly expensive and i could not find spare part. Just a little warning, do not ever buy NOX sensor from China. The thing does not work right away (broken heater element) or just pretends to work but gives data that are way too off what ECU expects. I am currently trying something like software emulator for NOX. BMW guys have NOXeM but no luck for Skodas. It has its own sub ECU and communicates with engine ECU via CAN bus so it can be tapped into.

Actually i thought that stratified mode is enabled only on European cars where fuel is low on sulfur. NOX cats after primary cats and NOX sensor are sign that car is equipped with true fuel stratified injection. Have your daughter's Golf achieved stratified mode?