DS3 thp misfire

[Doobrychat]

Hi all new on here as moved onto a DS3 thp model..

The cars been fine for 7 months and has 48k on the clock but thought it would be a good idea to service it over the Christmas break... Should've left it working as what's happened is a bit confusing...

New plugs, oil filter and air filter and secondary lambda sensor as was getting the 0054 code occasionally...

Anyhow I now have a misfire under load so scanned it cylinder no2, swapped 2 n 3 coil over and low and behold ño3 misfire, so ok new Delphi coil pack and low and still misfire on number 3 with new coil pack...ok move that to 4 and yes you guessed it 4 misfire... Ok faulty coil pack so send out another and still missing on 4, then put old plugs back in and still 4 missing. Spoke to remappers and Citroen dealers X2 and they all say coil pack but brand new genuine part and still missing after 2.5k under load...

All day messing about and I'm still none the wiser but just thinking they've changed the ohm resistance in the coils from 2011 to now..Also done a compression check and that's fine across all cylinders...

Can anyone advise please?

[Jamie@SPTuning]

Check fuelnpressure

[Doobrychat]

Can you tell me what it should be so I can check on live data..

Thanks

[Doobrychat]

Would I be right that it should be in the 70 bar region?
found that out on Google...

[V3nn3tj3]

48 to 50 bar on idle and 120 bar at peak.

[Doobrychat]

Ok have checked and have 48-50 bar on idle and 85 at 5-6k rpm..also 60bar at the point it misfires at 2.5k rpm..

Drive it like miss daisy no worries put it under a bit of load and then it misfires..

Thanks for the assistance so far..

[V3nn3tj3]

On a snap trottle it should go up to 120 and drop again. At 90kph it should be 80 at 120kph it should be a 100 bar.

[Doobrychat]

Sorted it with a genuine Citroen coil pack as it didn't like aftermarket ones... Go figure but thanks for your input guys

[Jamie@SPTuning]

Sorted it with a genuine Citroen coil pack as it didn't like aftermarket ones... Go figure but thanks for your input guys

I see no end of THP with new aftermarket coil packs that misfire, including DELPHI with black caps and also NGK. Some don’t have a metal shroud also. Always use genuine coil packs on these, which a have white cap. I’m sure they’re also made by DELPHI but they are definitely different.