Ez Efi 1.0 fuel injection. Anyone with experience with it?

Good day. I have the Fast Ez Efi 1.0 installed on my Demon. I been running the system for about a year now...Been through the electrical gremlins with it also replacing fuel pumps. The problem I'm having is under acceleration (anything more than 1/4 throttle) the AFR goes extremely lean and loses power and fall on its face ....15.8 or 15.9. If I back off the throttle she catch herself and start pulling with the AFR round 13.8....The fuel pump is "new"....Its not a Walbro but a pump I bought for a 98 Grand Cherokee with the 5.9 litre engine... (To bring in parts over here gets expensive hence the reason I gone with that pump)....I reset the tune after feeling the problem but it's still there. Any idea as what could be causing the lean condition?
13.5 idle afr
13.8 cruise afr
11.8 WOT afr