rx-711

iTrader: (2)

hey everyone need some help. i have my swap pretty much finished just need to figure out this stumble so i can try to make this my daily driver.

heres whats happening: when i am on the gas normal and start to rev it up it goes to 3500 and then stumbles real hard and will just keep stumbling and will not get passed there. now if i get on the gas hard it will either stumble once and the rev up or just rev straight through no problem and create boost and what not. i have driven the car around the block and it does this in every gear. I know that there is the infamous stumble when the injectors switch from primary to secondary but this stumble makes the car undrivable.

here a crappy video that kind of shows it

http://www.youtube.com/watch?v=dKoZZiMwEhE


now heres what the car is s4 na with jdm tII swap, stock turbo and top mount. rtek 1.7 with greddy 720 sec and stock 550 primarys, walbro fuel pump, full 2.5 in exhaust with cat and all emissions blocked off.

right now the only thing i can think of is maybe the 02 sensor becuase i do need an new one because i had to resoldier the wires and dont know if its working properly. other than this stumble problem this car runs so smooth and nice so i just want to figure this out. thanks for any help in advance and hope igave enough info.

thanks justin

dawicka2

Check and clean major grounds and check your wiring...

I would put a stock n332 or 3 ecu in and see if it still does it, then swap (temporarily) your original 550s for the 720s.

may do the trick....

i would also temporarily swap my s4 na afm in, to see if that is the issue. My afm allowed me to roughly rev the car just before not working at all, so it is possible.

Good luck with your issue.

john ny

rx-711

iTrader: (2)

well i think that i very well may have diagnosed the problem. i took the ecu out and put in a n.a. ecu and i was able to rev it with out any problem. so now i am in the dilemma of trying to figure out what to do with my rtek ecu whether i should send it in to be fixed or what.

barnett87rx7

iTrader: (1)

if you have the rtek usualy you need a safc to tune the fuel the stumble could be due to a bad switch between primaries to secondaries