New member needing help please

[Tom Fletch]

Hi all

I have a 66 plate Leon Cupra estate and about 4 weeks ago started having a misfire fault. I've always taken it to a Volkswagen specialist for servicing etc and had no issues with them, but they're struggling to find the fault.
They replaced the sparkplugs but that didn't fix it. They said the compression is ok and measured the timing chain to make sure it hadn't stretched and said it hasn't. They sent me to get it walnut blasted at a cost of over £500 and that hasn't fixed it.
At this point they have washed their hands of it. I've taken it to another garage I trust and they have swapped 2 of the spark plugs around and the fault is still on cylinder 3. Then they've swapped 2 of the injectors around (not the direct injectors) and the fault is still showing on cylinder 3. The exact fault codes are P030300 and P33B900.
Has anybody else had this and been able to get to the bottom of the cause? I'm really grateful for any help or advice. Many thanks

 

[Nathan penney]

Sorry I can’t help you, but I’ve never heard of walnut blasting.
Just had to Google it to see what it was.
Never knew such a thing existed.
Hope you get to the bottom of it.

 

[adam davies]

Hi all

I have a 66 plate Leon Cupra estate and about 4 weeks ago started having a misfire fault. I've always taken it to a Volkswagen specialist for servicing etc and had no issues with them, but they're struggling to find the fault.
They replaced the sparkplugs but that didn't fix it. They said the compression is ok and measured the timing chain to make sure it hadn't stretched and said it hasn't. They sent me to get it walnut blasted at a cost of over £500 and that hasn't fixed it.
At this point they have washed their hands of it. I've taken it to another garage I trust and they have swapped 2 of the spark plugs around and the fault is still on cylinder 3. Then they've swapped 2 of the injectors around (not the direct injectors) and the fault is still showing on cylinder 3. The exact fault codes are P030300 and P33B900.
Has anybody else had this and been able to get to the bottom of the cause? I'm really grateful for any help or advice. Many thanks

You haven't mentioned coil packs ?

 

[cupra14]

+1 coil -- swap #3 with another or even buy another & swap it in

 

[mjj4]

I agree with cupra14, swap a coil pack first, or check the grounding of the coils. This is a common problem on the EA888.3 and people fit this additional earthing kit to overcome the poor design. Have a read here:

Connect Motorsport Grounding Kit - 2.0 TSI EA888 GEN 3 Vehicles Only! - CMGEN3

This grounding kit is created and manufactured to offer a straightforward fix for a common issue on the MQB EA888.3.

www.akstuning.co.uk