rough on cold starts

[Filipelol]

Hello everyone,.
I've had my car for about a year now and every time I would do a cold start, the car would idle at 1.1k rpm for 10 or so seconds.
Until recently that was the case, but now, more often than not, when starting the car cold it jumps to 1.1k then immediately bogs down and almost sounds like its about to stall, and fluctuates rpm without pressing the throttle.
Here is the example, the first being the "good start" recorded yesterday, and the second one the "bad start" recorded today.  (same ambient temperature and coolant temperature).

()

 

 

Here what has been done to the car less than 1000 miles ago, all tho this would happen before.

Changed timing chain with the new kit "B"
Changed waterpump
changed oil from 30w to 40w
changed oil filter
changed air filter
cleaned MAP sensor

[Rooted]

What is the ambient temperature where you are?

 

Have the spark plugs been out and checked or replaced recently, 

or how long since they were?

[Filipelol]

29 minutes ago, AwaoffSki said:

What is the ambient temperature where you are?

 

Have the spark plugs been out and checked or replaced recently, 

or how long since they were?

12°C the lowest, but I've regular cold starts with warmer temperatures, about the spark plugs one of my spark leads failed 8k miles ago and I think my mechanic replaced all the plugs when that happened, altho I'm not sure, so next step check plugs ?

[Rooted]

That is what was one of the first things that needed doing so yes, plugs out, gap checked, and probably plugs replaced,

[mrgf]

Also, cleaned map sensor... Was this done properly? It may have been better fitting a new one.

 

[Filipelol]

3 minutes ago, AwaoffSki said:

That is what was one of the first things that needed doing so yes, plugs out, gap checked, and probably plugs replaced,

About the plugs I've the discussions about plugs for the vrs but none for the 1.2 tsi, what do you think would be the best, Bosh ngk or denso ? I know the Gap is 0.8

[Filipelol]

1 minute ago, mrgf said:

Also, cleaned map sensor... Was this done properly? It may have been better fitting a new one.

 

I used electrical contact cleaner that is plastic safe, this is what it looked like before, it had no gunk but had some oil on it 

[xman]

17 minutes ago, Filipelol said:

 one of my spark leads failed 8k miles ago

 

Let me guess.....no. 3?  Check the other leads havent gone open circuit or have tell tale burnt point where the insulation is failing and sparking across.

 

OE plugs are NGK IZFR6P7 pregapped at 0.7mm and are very good.

Edited 7 February, 2018 by xman

[Filipelol]

3 minutes ago, xman said:

 

Let me guess.....no. 3?  Check the other leads havent gone open circuit or have tell tale burnt point where the insulation is failing and sparking across.

Oe plugs are NGK IZFR6P7 pregapped at 0.7mm

The one that failed is the one with the protection, and the others look ok from the outside, or is there a better way to check them ? 

[xman]

Check number 3, that one usually fails because its resting on the exhaust shield. Pull it off at both ends ( use a proper spark boot puller - do NOT try to pull using the lead) and use a multimeter to check its not open circuit or very high resistance. Should be around 9kohm afaik. Examine for black marking on the insulation.

 

https://www.amazon.co.uk/Sealey-VS5293-Spark-Plug-Lead/dp/B001K4EAHY

 

[mrgf]

I am very aware that some sensors have an extremely fine wire, like a hair, inside and this can be damaged so easily. Not sure about this one but you could have cleaned it to death!

[Filipelol]

Just now, mrgf said:

I am very aware that some sensors have an extremely fine wire, like a hair, inside and this can be damaged so easily. Not sure about this one but you could have cleaned it to death!

The ones with fine wire are MAF sensors, and yes I'm aware but I think mine is fine as the readings seem normal and no codes so far.

[Filipelol]

2 minutes ago, xman said:

Check number 3, that one usually fails because its resting on the exhaust shield. Pull it off at both ends ( use a proper spark boot puller - do NOT try to pull using the lead) and use a multimeter to check its not open circuit or very high resistance. Should be around 9kohm afaik. Examine for black marking on the insulation.

 

https://www.amazon.co.uk/Sealey-VS5293-Spark-Plug-Lead/dp/B001K4EAHY

 

I think I will eventually change the rest of them for the ones with the protection, just haven't found the part nº yet.

[xman]

03F 905 409 C I think

 

https://www.ebay.co.uk/itm/VW-AUDI-SEAT-SKODA-TSI-PLUG-LEADS-03F905409C-GENUINE-SET/273047443777?epid=673707011&hash=item3f92e55941:g:3oYAAOSwBt5ZHBoz

 

And your spark plug options

 

https://www.opieoils.co.uk/c-2702-lookup-results.aspx?vehicleid=12328&variantlist=124622:235104,214135:0&yearFilter=2013

 

Just bought the Bosch ones to try on the Octavia. They are 0.8mm and higher supression resistance (6k vs 700 ohm) than OE NGK. Also about 0.5mm shorter reach.

Edited 7 February, 2018 by xman

[Filipelol]

46 minutes ago, xman said:

03F 905 409 C I think

 

https://www.ebay.co.uk/itm/VW-AUDI-SEAT-SKODA-TSI-PLUG-LEADS-03F905409C-GENUINE-SET/273047443777?epid=673707011&hash=item3f92e55941:g:3oYAAOSwBt5ZHBoz

 

And your spark plug options

 

https://www.opieoils.co.uk/c-2702-lookup-results.aspx?vehicleid=12328&variantlist=124622:235104,214135:0&yearFilter=2013

 

Just bought the Bosch ones to try on the Octavia. They are 0.8mm and higher supression resistance (6k vs 700 ohm) than OE NGK. Also about 0.5mm shorter reach.

Thank you very much, so can't go wrong with either plug right?

[xman]

I have only used NGK so far and they have been very good.

[Filipelol]

2 hours ago, xman said:

I have only used NGK so far and they have been very good.

Why change? And with different Gap and suppression resistance which would you think will be better with a remap

[xman]

Why change? The Bosch are half the price of the NGKs.

 

I inspected 8 NGK plugs (one set run 56k miles the other 85k miles) and the one weak point of the NGK seems to be the laser welded attachment of the small platinum disc on top of the ground electrode. The ground electrode wears away from one side and ultimately the microscopic disc detaches (happened in 2 of the 8 plugs, the ones that did 85k). Didn't stop them working though. On the Bosch the platinum bit is inset in the ground electrode and imo likely to survive longer than the NGKs. However not sure if the heat range is identical. We'll suck it and see......

 

In all cases the iridium tip on the centre electrode showed very little wear. 3 out of the 8 plugs were excellent showing very little wear at all. 

 

No. 4 cylinder 85k miles 1.2tsi platinum disc on ground electrode intact, best example

 

No. 3 cylinder 85k miles 1.2tsi ground electrode worn, platinum disc missing, worst example

 

Bosch plug with platinum inset into ground electrode

[Filipelol]

So today had a lot of misfires, dropped by the garage and went for a test-drive, misfires occurred on cylinder #1.

Last time my cable nº4 failed and was replaced, and the sparkplug for that cylinder, I thought they had changed all of them, so here are the plugs.

 

cylinder nº1 

 

cylinder nº2

 

Cylinder nº3

[Filipelol]

Cylinder nº4 

[xman]

Ugly. How long have those plugs been in?

 

Mixture is running too lean and/or plugs running too hot. What plugs are they? 

 

Plus lots of oil on the threads. You look as if you have a developing problem. They should come out dry, like mine.

 

And what kind of garage would replace just one plug? They obviously didn't even remove and check any of the others.

 

You've received very poor service.

 

 

Edited 20 February, 2018 by xman

[Filipelol]

Getting worried  I dont know for how long, I bought the car with 35k miles, and the plugs aren't oem, they are bosh so they cant be for that long?? , It now has 45k miles, the plug they changed was roughly 6-7k miles ago so I dont know what to take from this, and if plug nº4 should be worse or better with 6k miles (considering the others).

 

Any advice on what to make of it and what to check? Thank you

I'll take pictures of the lead nº1 and of the plugs to see if there are any clues.

Edited 20 February, 2018 by Filipelol

[Filipelol]

Dont know if could matter but I had the pcv pike broken since I bought the car, who knows for how long it was like that, and was using 5w30 oil, pcv fixed and using 5w40 now, can the oil be cause from a bad valve cover seal?

[Rooted]

?

What octane of fuel is it in the Azores 95 ron?

[Filipelol]

95 and 98, I use 95 but from time to time I put in 98, no often tho, you think it could have something to do with it?