TE310 2012 runs like garbage the first few seconds

As you can read in the Title my 310 Runs really bad the first few seconds after a cold start, if you blip the throttle a few times it "clears out". Really hard to discribe. Started happening after i installed the Racing kit with TXC Ecu and 12 Port injector, once the bike warms up it runs flawless. Not directly a problem, but quiet anoying. Has anybody else had this problem? I've reset the TPS and set the CO to 100, as i said once the bike runs fpr a few seconds no complaints.

Does it seem rich, is there black smoke and a fuel smell?
If it does then 2 possibles are leaking injector or coolant temp sensor

No smoke, just the normal cold-weather condensation until its warmed up.

need to do a full fuel system baseline before anything. check sensors, clear all lines, change filter, clean the new injector, dump the tank, etc etc just get the fuel system cleared out and baselined. Then go from there. They are finicky about that fuel system. we are just key punchers here you need to do the elimination trouble shooting, baseline, its not a new bike, valve clearances, compression, ignition system, clean the gen of magnetic debris, etc etc.

What fuel filter do these Bikes use? Cant find it listed in the spare parts catalog. New spark Plug, Valve clearance spot on. How would you clean the injector? Is the coolant temp sensor even a canidate if it runs good after just a few seconds? Pickup is clean, had it open just a few days ago.

I use the one from a KTM, "KL97 or something like that.

It is hard to reuse the fuel lines from the old filter. CA cycleworks sells hose kits and maybe the filter.