EPC Light Intermittent

[A3-BTFSI]

Hey guys,

So Im out of ideas, I have changed all spark plugs, coil packs as I was getting a EPC light randomly, restart sometimes and goes away, other times it happens over and over again and eventually goes away.
Did a VCDS scan and I am getting a misfire on cylinder 2, then 1, then 3, then 4 all random at different times, happens on start up when cold and also when the car os hot.

Car is stage 2 with supporting mods and tune.

Could it be leaking injectors or something else?

 

[AlS3BE]

check all the coil packs and if it’s consistently 1 or 2 cylinders then swap them around and see if you can make it go to other cylinders. Check the earths cables as well. One of my old car had a broken earth cable and randomly arc when it made contact swinging about. This caused havoc with electrics.
Could be plugs too hot or too cold of a rating for a stage 2.
Being a stage 2 is the fuel rail at adequate pressure and injectors has enough flow for fuel especially at higher gears as the demand for fuel is higher and for longer intervals.
Other than that see if you can get a factory map flashed back on to it to see if it’s a bad tune.

 

[A3-BTFSI]

check all the coil packs and if it’s consistently 1 or 2 cylinders then swap them around and see if you can make it go to other cylinders. Check the earths cables as well. One of my old car had a broken earth cable and randomly arc when it made contact swinging about. This caused havoc with electrics.
Could be plugs too hot or too cold of a rating for a stage 2.
Being a stage 2 is the fuel rail at adequate pressure and injectors has enough flow for fuel especially at higher gears as the demand for fuel is higher and for longer intervals.
Other than that see if you can get a factory map flashed back on to it to see if it’s a bad tune.

Thanks for the reply, all coil packs are new so swopping won't make a difference as the misfire happens in all cylinders but not at the same time, will start up and cylinder 2 will miss, then next day will start up and cylinder 4 will miss and so on.

Fuel pressure is adequate and no issues there, have had a fuel fuel system clean including tank, rails, lines and injectors.

The EPC light only comes on at startup and doesn't happen when driving even at redline smashing through the gears.

Will get in touch with my tuner and ask him to have a look as this was my next line of thinking.

 

[AlS3BE]

Did this start after a remap or after a service?

 

[A3-BTFSI]

Did this start after a remap or after a service?

Started about 1000km after bad fuel when I had to clean the whole system but car ran fine after all was sorted, it is happening more and more now.

 

[AlS3BE]

Started about 1000km after bad fuel when I had to clean the whole system but car ran fine after all was sorted, it is happening more and more now.

maybe the bad fuel has clogged the injectors. From what I read there’s no fuel filter on these cars.

 

[A3-BTFSI]

maybe the bad fuel has clogged the injectors. From what I read there’s no fuel filter on these cars.

Yeah also thinking that, needed to replace plugs and nothing wrong with some new coils too, will take it to get a carbon clean and injectors tested and cleaned.

 

[Damo S]

seems weird that it's random. if it was injectors at fault you would think a particular one or even all of them would flash up all the time not intermittantly. could it be perhaps the fuel pump itself?

the randomness in my mind points to something electrical.

what a pain

 

[A3-BTFSI]

New Plugs, new coils and same thing.

So everything is pointing towards blocked injectors, taken them to get cleaned and hopefully wont have to replace all of them.

 

[Tutiten]

New Plugs, new coils and same thing.

So everything is pointing towards blocked injectors, taken them to get cleaned and hopefully wont have to replace all of them.

Did you solve the problem? I have a similar issue.

 

[A3-BTFSI]

Did you solve the problem? I have a similar issue.

Ended up being my Turbo actuator that was faulty and evenly went bad leaving the car in limp mode, I have since upgraded to an IS20 turbo and changed out the engine speed sensor as was also giving a fault at the time. This fixed my issues.