Hi guys, i have a 99 spec with these mods , front pipe, mid and apexi catback, greddy intercooler, hks air intake, koyo radiator, hks ssq BoV, supra TT pump, sard fpr and apexi power Fc.

Its just been dyno tuned but we cant solve the random backfires when shifting gears and when i take the foot lightly off the pedal, when i say random i mean really random, sometimes it shifts ok without any backfiring, other times it pops like mad scarying motorist nxt to me ( this is all when shifting gear around 2-3k rpm) other times when i take my foot lightly off the pedal it feels like the cars about to choke than starts popping, but most of the time its ok.
Any idea what the problem is ? could it be my Blow off valve causing this?
any help would be greatly appreciated . thanks

 

bump

 

I would say your tuner isn't finished. Or doesn't really know how to tune it well in the first place.

Dave

 

I have my boost gauge tapped into my map sensor line. One time, my boost gauge hose fell off the gauge and the car acted exactly as you've explain. Random backfiring when slightly lifting off the throttle. It wouldn't hurt to check the hose leading to the map sensor for any pin hole leaks.

Liem.

 

thanks alot liem, i will go check it

 

Sounds like your a little rich still... The map needs to get cleaned up. Could also be some shitty plugs not firing all the time but thats a rare chance.

 

i'm pretty sure its from you running rich. i'm only running 8 lbs on 99 spec turbos with a lot of mods.. and most the time when i shift it'll backfire.. just little pops here and there. nothing to be worried about. just get it tuned a little finer

 

this 99 spec is like a problem child.. took it back to the tuner today, on my drive there is was popping now and than.
When we reach the workshop, my tuner hooks up his lap top and we go for a drive , the car doesnt backfire at all....this car is messing with me...sighs