i swapped in a jdm h22a about 7months ago, put in the following mods before the engine was installed in the car:
-crower valvesprings/titanum retainers
-ferrea valves
-type-S pistons w/ oem usdm h22a1 piston rings
-aem FPR and fuel rail (set to 40psi wot)
-eagle rods

everything runs strong and fine, but when i first start the car and before it reaches normal operating temp, if drive and come to a stop the engine will go almost to zero RPM and almost stall out, on rare occasions it will even stall out if i do a sudden stop. but once the temp guage reaches normal temp, it drives normal, it sometimes will go + or -10 rpm when idling long but it is barely noticable.

5 months after the swap, the autotensioner failed and i replaced it, ran for about 3 weeks then broke again all the oil leaked out of the tensioner.. im in the process of converting to a manual tensioner atm..

i suspect that maybe the crower valvesprings/retainers are making it harder to turn the cams and putting too much pressure on the autotensioner, but converting to manual tensioner probably wont fix my idling problem, anyone have any ideas on what it might be?
could it also be fuel tuning? since i am running type-s pistons with stock jdm cams?