R34 gtt idle problems and bad running
So basically as title suggests i have an r34 gtt. Basically stock except using power fc with rb25neo, steel bearing turbo tuned to 13psi, and walbro fuel pump (255 i think? Cant remember exactly)
Her idle is running terrible. Constantly hunting idle making it sound like its got fat cams lol, and even worse when cold and cold nights. Tends to surge on cruise speeds (60, 80, 100) as well and a light throttle tap temporarily stops it. Under boost she pops alot on revs over 4k and just found that shes making sucking noises under the hood somewhere, IAC have been removed and no gunk is inside but cleaned and replaced anyway.
Just today she started getting worse, started making a weird (soory for the silly description but its all i can associate it to) robotic kinda wirring noise everytime it tried to raise the idle rev during hunting and then stalling not long after. Will attach video link.
Ive taken it to multiple mechanics and all just seem to be trying to drain my money coz ill get the car back "fixed" but its not and all they say when i bring it back is "no idea why its doing that". Its driving me absolutely insane... just want her to run right as shes currently my daily
Any help will be amazingly appreciated, shes due to go into a new mechanic that specializes in rebuilds but even they say they may not find the problem.