rb25 problems..

[yanay]

im getting lots of small problems here and wondering if someone can help me out.
i just hooked up my 02 sensor and it was idleing great no smoke etc as soon as it got connected the idle got really bumpy and started burning black with lots of smoke. thoughts? i tested all the wiring and i have 2 small brown wires and sheilded thicker one. the only one the output any voltage was one of the small brown ones so i hooked that up to the black wire on the 3 wire o2 sensor

another thing i had noticed was my car will die if the battery ground is removed? thoughts ? shouldnt it continue to run ? i know the alternator is good because i can idle it all day off the battery..

as well my maf was a 4 pin s1 maf and i have a s2 motor so i put a s2 maf on it since my other one wasnt working properly and its staying in loop mode.. i went by the diagrams and tested each 3 wires and they all showed correctly one showed 12v one showed nothing and third showed 1.57 v any thoughts?
really need to get my dd back

[yanay]

anyone??

[92GTSTproject]

clean your s1 maf put it back on buy new o2 sensor change plugs

[yanay]

plugs are new just regapped last night to .7

[evolution23]

if runnin 12+psi run a .8 gap, if running below 12psi run 1.1 gap. i was running 12psi with .8 gap, turned down the boost and start misfiring twice as much and wouldnt boost as nicely. but i dont think plugs are your problem. might be contributing to it but i personally would just regap and look else where.

[yanay]

if runnin 12+psi run a .8 gap, if running below 12psi run 1.1 gap. i was running 12psi with .8 gap, turned down the boost and start misfiring twice as much and wouldnt boost as nicely. but i dont think plugs are your problem. might be contributing to it but i personally would just regap and look else where.

Well I've noticed that if I boost (generally 10 psi for a 5 second pull) it misses than starts blowing super rich and black and dies out. Flooding the engine almost like the plugs are getting blown out

[gtst_type_m]

what are you running for coil packs maybe its time to upgrade them if there the old oem ones

[yanay]

they look to be factory ( recently bought the car) but very very good condition coilpacks. no cracks but i have already done a reseal on them just to be safe.. i have done everything i have read about that could be the problem but nothing is it.
blew my turbo so i did

new external wastegate
new turbo
new turbo mani
new exhaust and intake
now it wont idle.. runs rich pops when idling misfires in boost.. everything you can think of..
i changed the plugs cleaned maf.. replaced maf, cleaned up TONS of haggard wiring, replaced plugs, checked vacuum lines, attempted to check codes.. ( no lights in ecu), did a full grounding kit on the motor. (4 gauge from battery ground-->strut tower-->intake manifold w/factory ground, as well i ran a 8 gauge from turbo manifold to firewall.) timing was never touched. anyone have anything else i can look at.. like i said the maf is still in limp mode so i guess first things first i have to get it out of that to see if maybe it is running better after gapping the plugs down again.. i put the s1 maf in again and wired it just like before with issue still it just hits a rev limiter at 2500 rpm but since putting the s1 maf back in i can start the car with the maf plugged in (s2 maf wouldnt even let me start it with the maf plugged in)


ANY HELP WOULD BE AWESOME I APPRECIATE EVERYTHING SO FAR!

[Skym]

Make sure you wired o2 sensor properly. If went rich after plugging it in, could be wired incorrectly. I would consult a auto electrician who is familar with Nissan's.

On boost sounds like engine is knocking (or excessive engine noise from missing caused by wide sparkplug gap) and ECU is switching to knock maps. Only solution (especially if upgraded turbo, exhaust manifold, etc that make engine run leaner) is ECU tune with bigger injectors, fuelpump to suit. With ECU on a lower budget, you could fit a Z32 ECU with Nistune (makes it retuneable like an aftermarket ECU via consult plug) that's modified internally to plug into factory loom with Z32 AFM + Z32 AFM plug or Link G4 ECU, optional IAT sensor, boost control solenoid. Link G4 ECU fixes alot of the problems (don't need MAF as uses MAP sensor, onboard boost control when used with aftermarket boost control solenoid, etc).

Not reving above 2500rpm happens when MAF is unplugged. Sometimes wiring problems are not at MAF plug, but between ECU, MAF or at ECU plug (or ECU plug is not seated correctly when bolted down and has crossbow shape to it).

[yanay]

how can i test my knock sensors? where are they located on the engine?? I was thinking of running a safc with a dyno tune.. whats your opinion on that? i just need to wait until i can afford new injectors for the engine.

[evolution23]

for the coils if its cracked it will be hairline and just below the writing, might want to check again. can be very hard to see. also double check your gap, regap if needed. i think your issue is with your o2/maf tho. since im running 10psi mine are gapped at 1.1, at .8 the misfires were mostly at idle but the car would run really rich after boosting. now with proper gap it is getting a much better burn. check your wiring though. MAF and O2. maybe wrong part? and change the maf back so you can eliminate that as the cause. atleast the car ran with the old maf right?

[Skym]

Knock sensors are located on side of engine under intake manifold. Would get knock sensor error code on ECU when knock sensor fails. Knock sensors probably will be picking up excessive engine noise (missing due to wide sparkplug gap, faulty / weak coilpacks, etc) that ECU thinks is knock.

SAFC intercepts signal / voltage from MAF and makes ECU select certain load cell on both fuel, ignition maps. You're limited to what's on stock fuel, ignition maps and if ECU decides to switch to knock maps when tuning SAFC, tune is ruined. When tuning stock ECU you turn off knock control on ECU to prevent this from happening.

Apexi used to sell SITC that adjusted CAS signal to play with ignition timing, to get past the limit's of what's on ignition map and worked with SAFC until PowerFC was made that replaced them. These days they only recommend SAFC to be used with podfilter, catback exhaust mods on R33. Anything more that and they mention to fit PowerFC. Tuneable ECU allows you to tune beyond factory ignition, fueling map limit's and extract more hp from engine.

If you keep boost level low with a good ECU tune with modified Z32 ECU, Z32 AFM+ plug / tail, fuelpump upgrade (wired correctly), FPR upgrade, the stock injectors should be more than enough. Getting a good tune is more important on RB25DET due to being high compression engine that's sensitive to tune being correct and first tune cost's the most. Retunes / touchups to add injectors, etc (when you can afford them) cost's a fraction of that once you have good base map to work from (first tune).

[yanay]

for the coils if its cracked it will be hairline and just below the writing, might want to check again. can be very hard to see. also double check your gap, regap if needed. i think your issue is with your o2/maf tho. since im running 10psi mine are gapped at 1.1, at .8 the misfires were mostly at idle but the car would run really rich after boosting. now with proper gap it is getting a much better burn. check your wiring though. MAF and O2. maybe wrong part? and change the maf back so you can eliminate that as the cause. atleast the car ran with the old maf right?

the coils are definatly not cracked but i taped them up anyway. what size of turbo are you running with that gap?

[Sharkus29]

Pressure test your system for leaks Josh. And if you want to try different coils use my old GTR ones that are in shelbes garage

[yanay]

got it had to trace and re run my wires for my maf from my ecu got it working well. Took it for a nice little cruise last night with zero complaints other than when coming to a stop it has a 400 rpm idle.. it would not die but just idle low put it sideways for the first time in a while.. always a good feeling . now just need to find out why the low idle and how to get it to stop boosting over 10psi. i have my vacuum line from compressor housing ran to a T one to the ebc and one to the side of the wastegate
than ebc to the top of the wastegate. i can set my lowest on my ebc and still over boost to 12-13 psi