2.0 FSI Poor idle when cold

[saabman]

Just come across this interesting video about the Cold start misfire issue and how to fix it - clean the inlet valves ..

BUT more importantly it has a nice section in the video about WHY it causes the problem, basically disturbed airflow causing lean mixture at spark plugs resulting in misfiring

Tsi cold misfires explained - YouTube

[MEL744]

Excellent video, explains why if you turn it off and on again the problem goes away, because the engine must switch from stratified to homogeneous mode. I was having a look at BVY in the wreckers, seems like you do have to pull the injectors to remove the flaps to get to the valves. But I noticed with the method he uses you don't need to remove them.

[JustCruisn]

Would the hydrogen clean by one of these services work ?
Carbon Cleaning - Carbon Cleaning Australia

[MEL744]

From what I understand, no it won't, there is just too much to remove and the deposits are too stubborn. The only options are chemical soak + scrub or media blasting which both require the manifold off.

[saabman]

Excellent video, explains why if you turn it off and on again the problem goes away, because the engine must switch from stratified to homogeneous mode. I was having a look at BVY in the wreckers, seems like you do have to pull the injectors to remove the flaps to get to the valves. But I noticed with the method he uses you don't need to remove them.

THere is not much room past the flaps - I had a go at scraping the crud off and also soaking in carby cleaner and soaking and scraping, neither were successful. just not enough room. Trying with a small media blaster might work. I was thinking of using walnut shell Green Abrasives - IBIX Australia

It looks like Ive got the car for a while so might have a go. Im taking a fair bit of time of work in a couple of weeks so might get some projects out of the way before I go back

[saabman]

This might be an option as well it claims its safe for bearings etc. and if its used in conjunction with a vacuum might be suitable and disolve the residue out with some carby cleaner

Safe Soda Blasting Soda - 4.5kg | Supercheap Auto

[saabman]

Well I’ve bitten the bullet and decided to give it ago.

Super cheap while they advertised blasting soda they don’t actually seem to stock it anywhere and it’s not available for online ordering ....

Found some at Total tools TTI 5kg Air Blasting Soda Media TTISODA5KG | Total Tools

So have orders that a mate will collect it tomorrow for me

As for the hardware everything I have seen looks rather cumbersome And expensive and considering the tight constraints to get into the valves in the BLX motor with out removing the injectors - I was looking at a DIY solution and come across this idea which is nothing more then a length of hose and an air blower.
Build Your Own Soda Blaster Cheap!

So I have all the pieces here and my air compressor is somewhat capable so air supply won’t be an issue.

I try and give it a shot on the weekend and see how it goes.

[saabman]

Would the hydrogen clean by one of these services work ?
Carbon Cleaning - Carbon Cleaning Australia

I just had a bit of a look at the hydrogen cleaning and they make some vauge claims about cleaning the valves but I cant see how it could possible work on the valves as the theory behind its opperation is to raise the combustion temperature to burn of the carbon. given the carbon that is a problem for these FSI engines is out side the combustion chamber youd be meltin the valves before it go hot enough to make any change.

Mechanical cleaning process is the only way.

[MEL744]

Exciting stuff!! Looking forward to hearing about how it goes.

[saabman]

Things got a little delayed to day after my 3 year old dislocated his elbow - all good now.

Got the manifold out and had a bit of a poke around - pulled the plugs out to make turning the engine over a bit easier.


made up the blaster Im not sure how effective its going to be as the clearance past the flaps is very narrow

so needed to reduce the pipe diameter which will waste a lot of energy. It does suck and blow material out so it might work ...


The plan is to give it a shot tomorrow and see how it goes - I still need to make up a reducer for the vacuum cleaner to suck the crud out nothing a bit of duct tape cant fix