hi everyone.. sorry if theres already a convo about this did a quick search but didnt find something that matched my problem
anyways
i got an r33 pretty stock apart from front mount, 300zx air flow meter, pod filter. and exhaust..
got a bit of a problem with the boost..
when drive it with the foot the the floor at about 3000-3500 rpm the car starts popping and backfiring badly the power just drops
but if i'm in 2nd and i hold the throttle about half way so the stock boost gauge is just over the 0 mark it runs smoothly to the red line then when i shift to 3rd have to hold the boost gauge on the 0 mark for it to run smoothly and so on 4th and 5th..
is this a fuel air ratio problem or spark plugs or fuel pump problem any ideas????
thanks