just put new spark plugs on my car and new coil packs to solve the problem of juddering and backfireing under boost and it still does it ,
have cleaned the boost solenoid what else can it be,
it has only done this after i fitted a chip and was fine before please help
matt

 

maybe the chip

 

i have thought that myself but its a scott .t chip and he is the best in the buisness so i forked out on bits but i dont no

 

does the chip settings match your setup ? i.e. is it mapped to your car?

 

mine did the same thing and it was my coil packs but like you have said you have changed them (for new i presume)
is yours an import or uk,
if uk make sure all pins are slotted in correctly,
if import has it been soldered in properly.
send scott a pm hes very helpful (i would be very surprised if theres anything at fault with the chip itself)

 

What gaps are you running? Somewhere around 0.65-0.7 tends to work better with increased boost than 0.8. Worth a try?

 

my plugs are gapped at 0.7 they are pfr7b
the car is a import sti 2 it has a 7k ecu in it and runs ok on that alone,spoke to scott about the numbers on the chip and they match the ecu but im only getting problems with it in
car goes well upto 4k then it start to lose power backfires and stutters but keep foot down and the last revs seem ok but not 1.1 bar ever
the chip is properly fixed in as have took it out and back in,the 7k has a socket for the chip anyway

 

Remove the chip and reconnect the J1 link and retry. If the car still does it then you know the chip is fine.

 

right then i have wound the actuator arm out and car runs fine but not getting 1.1 so ill wind back in until i get as close as i can without naty things happening