flubber or blubber when shifting under heavy load

[madracer36]

my son and i have put a port and polished head on his ka24e [single overhead cam],stainless steele valves, stiffer valve springs, removed swirl control valve and plugged holes from swirl valve shaft, removed egr,and all related control components. two questions;starts good cold, WILL not start when it has any amount of heat built up in engine, any thoughts about this problem. also, runs real good under NORMAL driving conditions, but when under HEAVY load, when shifting it has a serious blubber during the shift. have played with timing a bit to no avale. had oversized injectors in on intial start up [the kids idea], started hard cold and ran a lil rough so removed and installed stock injectors, starts good cold, runs good, but still wont start hot and has the blubber when shifting, no tuning to ecu has been done. just lookin for ideas on how to fix hard start issues when warm and also answers to the shifting blubber........also, has stage 2 performance cam from O andJ performance out of florida, just trying to get this thing tuned in for the kid to go play and the drag strip a little bit........any and all ideas welcome.

[madracer36]

Update: simple fix, just had to go down the list checking everything. Found heavy corosion at the temp sensor for the ecu connector. Went to spare parts truck and pulled sensor and pigtail harness out of it and installed on it, runs like a champ. Turned out to be fairly painless.