Ok, I have a semi built gsr motor that when I hit vtec at 5800, she will stall alittle after vtec hits then pull hard again around 7800 rpms. I have a p61 spoon ecu. Never had this problem before, just happend recently. Also coolant out of my radiator sometimes gets backed up into my reservoir, and battery won't stay charged. (yes I have a new battery) Someone throw me some ideas.

 

Is it over heating? Any codes? Is it backfiring at idel or before it starts want to die out? Do you have a hard time turning it on?

 

battery not staying charged would be alternator... I would think. or check your all your grounds.

as far as the coolant I would bleed the system make sure there are no air bubbles.

the vtec.. I don't know. maybe its the aftermarket ecu...

 

No codes, temp. stays cool, idles perfect, and starts up fine. Sometimes battery will stay charged and after awhile will completely be drained. Already rebleed the system and no air bubbles, and the vtec problem just happened. Was fine before.
Also no other ecu will work in my car except the p61 spoon ecu. Very weird. Any ideas??