rb25 help needed - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

yanay · 04-29-2012, 09:14 PM

hey guys cant seem to get any answers on most forums so i thought i could try here..
series 2 rb25
gt3076r
stock manifold modded for external wastegate
3" full exhaust
stock injectors
walbro 255
fmic
chopped factory intake for 3"
i blew up my factory turbo and got a good deal on the gt30 so i thought what the hell..
hooked everything and started her up and i have a very very low idle with lots of popping. as soon as i boost i get a mad hesitation on WOT and if i put the clutch in and pop it in neutral it will die out instantly than not want to start. its been driving me crazy over the last week trying to diagnose it. it seems its running rich at some points and running lean at some.. the only thing i can think of is the 02 sensor is not wired properly.. i have 3 brown wires 1 dark 2 light and the 02 sensor has 2 white and one black. i assumed the dark to dark and light to light but could be far off.
i have a wideband and adjustable fpr on the way and i just need the car to run with 7 psi so i can get it to the tuning shop in calgary.. (250k) to get a dyno tune and injectors thrown in.
ive searched everything and tried so much and im pulling out my hair here.. anyone have ideas?!

Sileighty_85 · 04-29-2012, 09:20 PM

Sounds like a Vac/boost leak.

Plus the Stock ECU doesnt like any more boost then stock. It will then pull timing and dump fuel.

and no 7 psi on a GT30 is not the same as a 7 PSI on a factory turbo. Thats one reason why it runs like shit.

*fliprayzin240sx* · 04-29-2012, 10:23 PM

Like already said, DO NOT DRIVE THE CAR INTO BOOST WITH THAT TURBO WITH NO TUNING!!! Keep at it and you wont make your tuning session since you're engine will be blown.

yanay · 04-29-2012, 10:31 PM

hmm okay.. anything else you guys can recommend ? can i tune it as is without extra parts getting put on..? i have my maf 5 inches away from turbo and the filter pointing down. can that cause issues? i just want to get it half ass ready for tuning so im not paying out the ass for them to fix little shit for me at autodream..

Sileighty_85 · 04-29-2012, 10:39 PM

Umm you think Stock 370cc Inj and stock MAFS are enough to run a GT30.... Jesus.

Search around kid for a proper fuel system setup...

Or just save your self the trouble and drop a grenade under the hood.

EDIT: Also Welcome to Zilvia Hope you enjoy your stay....

yanay · 04-29-2012, 10:52 PM

doesn't hurt to ask.
Plan is injectors, adjustable fpr and a wideband right away.
Im not asking if i can rip my car around boosting the hell out of it with stock fuel setup. ( i havent boosted past 5 psi with it) and it was 2 pulls)
im simply asking if i can get some help figuring out why i cant idle it. and it sounds like hell just sitting in my driveway or if anyone knows the wiring setup on the 02 sensor or can point me in the direction of what to go over. ive check coils and they are like new. im about to test my maf ive gone over all my vacuum lines and cant find a leak

yanay · 04-29-2012, 10:55 PM

the turbo is a precision 5252e i was told its comparable to a gt30

yanay · 08-26-2012, 05:38 PM

hey so little update. checked with autodream and they told me it will be fine to run the turbo with the setup i have.
I have been driving the car for months now with no issues 6 psi on the turbo is hitting 11.6 afr at wot 14.6 at idle and 13.9 cruising.
still cant figure out why it wont idle after free revving in neutral tries to die out.
cleaned iacv checked vaccuum leaks etc

04-29-2012, 09:14 PM	#1
yanay Join Date: Apr 2012 Location: medicine hat Age: 31 Posts: 18 Trader Rating: (0) Feedback Score: 0 reviews	rb25 help needed hey guys cant seem to get any answers on most forums so i thought i could try here.. series 2 rb25 gt3076r stock manifold modded for external wastegate 3" full exhaust stock injectors walbro 255 fmic chopped factory intake for 3" i blew up my factory turbo and got a good deal on the gt30 so i thought what the hell.. hooked everything and started her up and i have a very very low idle with lots of popping. as soon as i boost i get a mad hesitation on WOT and if i put the clutch in and pop it in neutral it will die out instantly than not want to start. its been driving me crazy over the last week trying to diagnose it. it seems its running rich at some points and running lean at some.. the only thing i can think of is the 02 sensor is not wired properly.. i have 3 brown wires 1 dark 2 light and the 02 sensor has 2 white and one black. i assumed the dark to dark and light to light but could be far off. i have a wideband and adjustable fpr on the way and i just need the car to run with 7 psi so i can get it to the tuning shop in calgary.. (250k) to get a dyno tune and injectors thrown in. ive searched everything and tried so much and im pulling out my hair here.. anyone have ideas?!

04-29-2012, 09:20 PM	#2
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Sounds like a Vac/boost leak. Plus the Stock ECU doesnt like any more boost then stock. It will then pull timing and dump fuel. and no 7 psi on a GT30 is not the same as a 7 PSI on a factory turbo. Thats one reason why it runs like shit. __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

04-29-2012, 10:23 PM	#3
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	Like already said, DO NOT DRIVE THE CAR INTO BOOST WITH THAT TURBO WITH NO TUNING!!! Keep at it and you wont make your tuning session since you're engine will be blown. __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

04-29-2012, 10:39 PM	#5
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Umm you think Stock 370cc Inj and stock MAFS are enough to run a GT30.... Jesus. Search around kid for a proper fuel system setup... Or just save your self the trouble and drop a grenade under the hood. EDIT: Also Welcome to Zilvia Hope you enjoy your stay.... __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

04-29-2012, 10:31 PM	#4
yanay Join Date: Apr 2012 Location: medicine hat Age: 31 Posts: 18 Trader Rating: (0) Feedback Score: 0 reviews	hmm okay.. anything else you guys can recommend ? can i tune it as is without extra parts getting put on..? i have my maf 5 inches away from turbo and the filter pointing down. can that cause issues? i just want to get it half ass ready for tuning so im not paying out the ass for them to fix little shit for me at autodream..

04-29-2012, 10:52 PM	#6
yanay Join Date: Apr 2012 Location: medicine hat Age: 31 Posts: 18 Trader Rating: (0) Feedback Score: 0 reviews	doesn't hurt to ask. Plan is injectors, adjustable fpr and a wideband right away. Im not asking if i can rip my car around boosting the hell out of it with stock fuel setup. ( i havent boosted past 5 psi with it) and it was 2 pulls) im simply asking if i can get some help figuring out why i cant idle it. and it sounds like hell just sitting in my driveway or if anyone knows the wiring setup on the 02 sensor or can point me in the direction of what to go over. ive check coils and they are like new. im about to test my maf ive gone over all my vacuum lines and cant find a leak

04-29-2012, 10:55 PM	#7
yanay Join Date: Apr 2012 Location: medicine hat Age: 31 Posts: 18 Trader Rating: (0) Feedback Score: 0 reviews	the turbo is a precision 5252e i was told its comparable to a gt30

08-26-2012, 05:38 PM	#8
yanay Join Date: Apr 2012 Location: medicine hat Age: 31 Posts: 18 Trader Rating: (0) Feedback Score: 0 reviews	hey so little update. checked with autodream and they told me it will be fine to run the turbo with the setup i have. I have been driving the car for months now with no issues 6 psi on the turbo is hitting 11.6 afr at wot 14.6 at idle and 13.9 cruising. still cant figure out why it wont idle after free revving in neutral tries to die out. cleaned iacv checked vaccuum leaks etc