rhd type r

ok so i have been workin on a friends 95 si. when i started workin on it it had a stock gsr swap. a lot of things went wrong with the swap. so he asked us to put a together a high compression gsr for him. the engine he has in it now is a gsr block, ls crank, ls rods, and usdm b16 pistons. it should have a compression ratio of 12.3ish:1 then we find out that the head wasnt milled .010 it had alot more taken off than we were told. so we did a compression check after the engine was broke in. we estamated it between 325-335 psi on each cyl.(my gauge only goes to 300psi.) so everything runs fine, nothing seems to be wrong. the Unlucky guy gets the car back and drives it for a while and says "its doing the thing it was doing before." although he didnt tell me before it had a problem....so long story here is the problem. when you put in the clutch from a high rpm the engine cuts off. usually it fires rught back up. but occasionally, at compleetly random times when it cuts off it wont fire up and the fuel pump doesnt come on.
thanks for any advice yall can give.

mark