Random misfires

[jamieibizaFR]

Hi all,
Having an ongoing issue for a long time now with my 2014 Ibiza 1.2tsi (105) , under light load the engine will randomly stutter which is the engine misfiring but isn’t as violent as the car is under light load , under heavy load acceleration the car violently misfires as if someone has put an invisible brick wall in front of you . This issue will occur at random times during acceleration I am not receiving any fault codes and have recently had new iridium plugs, new coil and new HT leads .
Thanks ,
Jamie

 

[mty12345]

I'm 99% sure the 1.2tsi is a direct injection engine, if so then it could well be carbon build up on the intake valves. This era of engines was notorious for it.
Another possiblity could be the turbo actuator, but i'd expect to see a fault code for that.

 

[jamieibizaFR]

I'm 99% sure the 1.2tsi is a direct injection engine, if so then it could well be carbon build up on the intake valves. This era of engines was notorious for it.
Another possiblity could be the turbo actuator, but i'd expect to see a fault code for that.

Thanks for the reply ,
It is indeed a direct injection but the strange thing is I’ve recently had a carbon clean done on the car I’ve had this issue ongoing for over a year now , power just randomly cutting mainly under heavy acceleration it feels quite violent I’m quite stuck with what to do .

while I had the carbon clean done I also got a stage 1 tune and after he was done I asked if he could check the injectors but he said they are all firing okay , but with it being random could one of the injectors just not misfired when he tested it ?
Also I have a high and lumpy idle sometimes it’s normal idle but still lumpy

 

[mty12345]

Ah right, that rules out carbon build up then, lol.

Have you checked for any split PCV pipes? Leaks there can cause a high and lumpy idle and also hesitation under acceleration. If not, then give them a good look over with the help of a torch, and give them all a gentle squeeze as sometimes they can have splits which are hard to see.

I think the best think to do would be to find someone with VCDS or a professional level scanner, and then do some driving while running logs of the live data. Logging:
RPM
MAF
Boost requested vs actual boost
Fuel requested vs actual fuel
Fuel trims
The misfire counter per cylinder

That would probably give you a good idea of the problem.

 

[jamieibizaFR]

Ah right, that rules out carbon build up then, lol.

Have you checked for any split PCV pipes? Leaks there can cause a high and lumpy idle and also hesitation under acceleration. If not, then give them a good look over with the help of a torch, and give them all a gentle squeeze as sometimes they can have splits which are hard to see.

I think the best think to do would be to find someone with VCDS or a professional level scanner, and then do some driving while running logs of the live data. Logging:
RPM
MAF
Boost requested vs actual boost
Fuel requested vs actual fuel
Fuel trims
The misfire counter per cylinder

That would probably give you a good idea of the problem.

I’ve also just added an oil catch can on crank case vent (out) I removed small foam insulated pipe going to turbo and added two 90degree pipes to install it it’s caught water from condensation and a little oil since I installed it yesterday.
I also replaced both the vent valves ,
the little pcv that vents air in at the back of valve cover and larger one at side of valve cover that vents gases out to turbo intake )

no splits or cracks either I think my only option would be to take it to VAG professional.
last time I took it to one I was charged £800+ for no start issue which was coil and leads , they changed oil etc and did mot but still was incredibly steep pricing

 

[mty12345]

Yeah sounds like that might be the best option for the car, probably not for your wallet though.

 

[Ara01234]

Hi all,
Having an ongoing issue for a long time now with my 2014 Ibiza 1.2tsi (105) , under light load the engine will randomly stutter which is the engine misfiring but isn’t as violent as the car is under light load , under heavy load acceleration the car violently misfires as if someone has put an invisible brick wall in front of you . This issue will occur at random times during acceleration I am not receiving any fault codes and have recently had new iridium plugs, new coil and new HT leads .
Thanks ,
Jamie

Hi, I have exactly the same issue with my Seat Leon car randomly misfires did you manage to resolve the issue with your car?

 

[jamieibizaFR]

Hi, I have exactly the same issue with my Seat Leon car randomly misfires did you manage to resolve the issue with your car?

Unfortunately I haven’t found the issue I’m beginning to think it’s an actuator issue as I have ruled everything else out , is your’s a tsi engine ? I have even plugged a snap on code scanner and an expensive autel code reader from work (I’m a technician) and no codes at all , it’s a strange one , it was at its worst a couple of days ago I thought I had ran out of fuel the car would not boost at all in first seconds or third gear until I turned the car off and back on and was like normal but still have the random judder or violent jolt under acceleration