Rb25De+T Not Running Right

[zacc80]

Hey guys, well im new here so please tell me if this is in wrong place, So ive recently bought a r32 skyline with a rb25de+t conversion its a series 1 motor and is running a standard s1 ecu, so il describewhat its doing and if anyone could offer advice if it a mmon 25 thing or what to check that would be good, its running a wasted spark setup, fmic, has a green sticker afm, and standard turbo etc, so it has a real rough idle that jumps between like 500ish to 1500rpm and sometimes will stall, and under acceleration it doesnt realy go past 4500rpm it just hits boost and splutters and sometimes backfires, so far ive put a 500hp fuel pump in, checked the spark thats good, its been wired into a r32 loom and im wondering if i should change to a r33 loom to eliminate any faulty connections the previous owner has, or it could be a simple sensor, any ideas ? Thanks

[GTSBoy]

Standard NA or turbo S1 ECUs should have some trouble running a boosted NA motor. I've always assumed that people just used aftermarket ECUs to run these conversions. Are you sure that it has ever run well with the ECU that it has in it?

[zacc80]

im not entirely sure as i cant find much info about it from previous owner, is there something that causes them to not run well with a standard 25det ecu, i wouldnt think that would have caused a issue if its got like det injectors etc

[WYTSKY]

You can run a standard S1 turbo ecu with all the standard turbo gear.

What about injectors? are they replaced? factory turbo? factory na? from memory na's are 270cc and turbos are 370?

Also, cant remember my afm labels - is green label the turbo afm or na?

essentially you need to ensure all your air, fuel, spark is up to facotry turbo standard otherwise you will run into problems. ( you said wasted spark setup so it sounds like that should be covered)

The 32 loom on a 33 rb25 with im assuming a 33 s1 ecu? I can't comment as I have never done it. not sure of the complications.

Also exhaust - hopefully you have some form of upgraded catback otherwise the factory n/a exhaust with a turbo dump pipe will cause problems too.

You said it has a FMIC, does it have a Bov? and not an atmo one, but a proper recirculated one? could be causing your stalling issues if it's an atmo one - do you put your foot on the throttle then let off in neutral and then it starts hunting?

[Rbsongate]

I ran a standard s1 det ecu for my de+t just with a fuel cut defender and it ran mint on 10 psi so I would look past the ecu

[zacc80]

im pretty sure it has 25det injectors as they are a darkish colour and side fed, and i think de injectors are a pinkish colour ?

Yes has a wasted spark setup so spark should be good, walbro 500hp fuel pump so its getting plenty fuel to the rail,

Yes a 33 s1 ecu with the r32 loom, has had what i think is resistor packs installed on the injector wiring by ecu if that helps,

Yes its had a full roughly guessing 3 inch exhaust put in and yes its a plumbed in bov in plae of where the standard one goes.

i have a feeling its a wiring issue, or injector fault, as i took lead 3 off and the motor ran no worse than it is yet has plenty of spark, did the same of 4 and 6, but 1 and 2 would make it run worse, each cylinder has good compression aswell all were 150

[GTSBoy]

All the points in posts above are why I said you have plenty of opportunities for trouble running these conversions with standard ECUs. The green label AFM is not the R33 turbo one. So it doesn't match up to a turbo ECU. The only way to use the wrong AFM on a given ECU is to also use the "wrong" injectors....ie, the ones that match the AFM. But then you wouldn't have enough fuel to keep up with the turbo.

If the ECU is an NA one, then the timing map wouldn't suit the turbo either.

If you put a turbo AFM, injectors and ECU together, then it should work, as has been said in posts above. But it sounds like you have some other injectors, because the correct injectors for any of these RBs shouldn't need a resistor pack.

You need to get the numbers off the AFM, ECU and injectors is you can, and track down what they belong to as your first item of business. Second item is probably to test those injectors and see if they're all working properly.

[zacc80]

i know the ecu is a s1 25det i already checked that, im unsure about afm cause all my mates 25dets have a pink sticker and they have 3 wires where as mine is the green sticker and has 5 wires, do most people use a r33 loom for the engine bay and this connects up to ecu and most of the inside dash loom correct ?

and yeah i will check the injectors today for part num and see what they are cheers

[GTScotT]

This resource will help with the AFM:

http://www.paulr33.com/

Just to confirm that a green label AFM will work with both an R33 S1 and S2 ecu, no worries. It does sound like you either have an AFM or a TPS issue.

My guess is that the wiring to either of these is still the OEM R32 harness and you need to switch the wiring around. Check all your wiring, make sure everything is connected the right way.

[wolverine]

Green label AFMs are normal on a S1 R33DET

[zacc80]

just pulled am injector out, they are jecs a46-00 purple plug, are these sr20det injectors maybe ?

and yeah, i have a feeling its wiring cause it looks pretty dodgy to me and its hard to tell cause i havnt done it, so im going to try a mates tps and afm and if thats no help i think i might buy a r33 loom and start again

[wolverine]

SR20 purple tops are the same as RB25 purple tops.

[zacc80]

so then i have standard 25det injectors, so why would it have resistor packs installed? is this needed when using the 20de loom on a 25det ecu?

I will be trying a new afm and tps tonight so i will let yous know how i get on

[GTScotT]

it shouldnt have a resistor pack.......

maybe the old owner had RB26 injectors on his RB20.

rip out the resistor pack asap!

Like I said....... Need to check all the wiring and make sure everything is how it should be! Sounds like they didnt do the swap all that carefully.

[zacc80]

yea i thought it was odd to need resistor packs on the injector wirng from ecu when i thought they were same as rb20 injectors, so ive pretty much settled on buying a r33 loom so i can also run vct and have all the correct connections and nothing messed with, so if anyones from nz and knows of a cheap loom please let me know

[HR32GTS 4DOOR]

If you really want to replace the loom. Get another RB20 loom, switch over the injector pugs and put in another wire and plug for the VCT. Alos use the rb20 ignighter. All other plugs are the same if its a S1 engine.

[zacc80]

so im better off getting a new rb20 loom, what injector wires do i swap over ? and yeah its a series 1 running a series 1 ecu aswell, but dont the rb25 have different injector plugs to the rb20 anyway?

[GTSBoy]

Injector plugs, not wires. Put R33 plugs onto the R32 wires.

[zacc80]

ohh ok i understand now, so pretty much use the 20 loom and ignitor with a 25 injector loom, and everything else should be sweet to plug in and run, eliminating any faulty wiring ? also how would i go about hooking up the vct to the ecu ?

[HR32GTS 4DOOR]

Injector plugs, not wires. Put R33 plugs onto the R32 wires.

Yeah what I ment