intermittent misfire after remapped ecu?

[azzsmith]

Ok thanks topher, do you think a 4bar fpr would be needed?
The car the ecu came from had one. 

[topher]

i dont know if the injectors maxing out with that fpr in will cause a lean enough condition for the backfires.. thats usually more a sign of weak flow from the pump. Or sometimes even lean running from massive overboost will do it. still, if you have free access to a 4 bar fpr its worth trying. even if it feels better i'd get it checked out properly before trusting the map to be fully compatible with your hardware

[azzsmith]

Ok mate, weird thing is it only does it on really hash acceleration, if i drive "normally" its fine!

[Chris.]

Sounds like a lean misfire from my experience.  had the same issue...under load it misfired, partial load it was fine. 

Could also be a coil breaking down, I had that too.

Id be starting with the fuel pump like Topher said.  Get rail pressure logged on a dyno and make sure all is fine.

[azzsmith]

Thanks chris... should have mentioned that before i put remapped ecu in it was boosting to 0.7bar and now it's 1.3bar, does that sound about right?

[Chris.]

18psi sounds good.

just careful when its misfiring....dont want anything melted.

[azzsmith]

MELTED?! 
Do you think i should try putting in calibra injectors? I have them in the boot lol.

[Chris.]

No, probably make it worse.

If its your pump weak, like i suspect...only thing is a replacement intank pump, or put old ECU back on until you upgrade.
I cant see the FPR making a difference as 4bar gives 15% more fuel in theory.

[azzsmith]

Ok thanks chris, I was gonna buy a replacement coil pack tommorrow from vw and try that but should I try fuel pump first or maybe ignition amp?

The only reason I say about the injectors is that baxxy thinks the car it came off had bigger injectors but hes not 100% 

[Chris.]

Doubt its either, ignition amp usually go all the time causing continous misfire.

What injectors were in the car?  Could well be a overfuel now you have suggested that.  You would NEED to use exact same injectors as what the ECU was mapped on.