I ran it pretty hard tbh, but with the new build was a completely new engine,
i also rebuilt the head with new springs/retainers/valves/valveseals and there were no signs of any damage when the head and components were checked.

I did spray carb cleaner around all the vacuum lead whilst it was idling to find a vacuum leak, i will double check the PCV to intake mani pipes tho, thanks, ste

 

i double checked the PCV pipes and they look fine?

Anyone have any ideas as this is really getting annoying!

 

depending on if you replaced your intake manifold, it might not be sitting all the way flush, i put a obx r drag racing intake manifold on my h22 swap and i had the same problem as you and did everything you have been doing and in the long run i had to shave down the surface of the intake manifold because the 1992 h22 differed from the newer model, so u might want to check on that..... sorry thats all i can help

 

I put the same intake mani on as was removed, so that is ok and its all torqued up so its not loos.

I found what the problem was in the end, the cams are so much more aggressive, that the give inconsistant vacuum at low revs, so the ecu not understanding this over fuels it. All you have to do is reduc the fueling from 0-1500rpm on the map