rb25 s2 Misfire

[Zimm]

rb25series 2 swapped into my r32
using the rb20 coil pack and ignitor
misfires but not all the time
and its always #1 that is having problems

Changed coil pack harness still misfire #1
changed coil packs still same thing

but like i said it doesnt do it all the time one day its good other day its bad,

could it be ignitor problem?
Maybe wiring or ECU?

I plan on upgrading coil packs, but if its a ecu or wiring then that wont fix it

anyone know?

[krystalized_jdm]

Been working on my buddies s1 rb25. We were chasing ignition problems for a while, we dropped some fuel in the cylider that wasn't firing and it started going. Replaced injector not she runs good.

Not 100% helpful to your situation, just thought I'd throw it out there. GL

[Skym]

Injector loom (maybe plug or injector), ECU, coilpack on cylinder one. Series 2 ignition setup has the ignitors inside each coilpack (not inside ignition module hence it's smaller on Series 2 R33 RB25DET, R34 NEO RB25DET), due to can shut coilpacks off one at a time to check for faulty coilpack via ECU (with Consult).

A RB20DET I know of failed on cylinder one due to faulty ECU (does happen), as I think it ran leaner. He swapped engines, so it eliminated looms, etc and same failure.

[Zimm]

injectors are brand new im guessin its something to do with the spark, cuz when its misfiring and i unplug the coilpack on cylinder 1 doesnt change
so not really sure

[Zimm]

well i dont have tach signal from my ecu to cluster, i do have tach signal to the ecu tho, so im wondering if the ecu is faulty to begin with,

i was also thinking the ecu was bad when it was #1 that failed because doesnt tach sig usually come from the cylinder #1

[Zimm]

i guess question would be how would i know if the ecu is bad or how id go about fixin this problem

[Skym]

Sounds like coilpack. At first it's intermittent, then runs permantly on 5 cylinders. A temporary fix is dipping sides of coilpack in resin or tape the sides up to seal the crack on both sides of coilpack (along seam that joins two halfs of coilpack, just under mounting bracket on both sides, always cracks there). Some go to the extremes of fitting plastic washers under mounting bolts for coilpack mounting bracket, so coilpack mounting bracket is not grounded to head (not sure if I would do that, as plastic + heat = bad news).

RPM signal is from CAS to ECU, then to dash (can see this on pinout diagram in back of manual with wire colours, etc). I think 0, 120 degree, etc on ECU plug pinouts are the CAS sensor inputs.

With testing injectors, pull CAS of, turn ignition to 3, so have power to ECU and turning CAS shaft until hear each injector click is one way to know signal is getting to injectors. But will get CAS error code on ECU that needs to be cleared.

[Zimm]

ya all my injectors are working good,

I was thinkin of upgrading to ls1 coilpacks, less problems. Probably a good idea?

and

if im gettin rpm to the ecu then the CAS is good then something with the ecu is wacked that i am no gettin RPM then probably

[krystalized_jdm]

ls1 is a great swap, I've heard lots of great things but you are sacrificing looks. I perfer splitfire, and that's what I'll be getting this upcoming winter season.

[Skym]

Encoutered a Silvia with same problem, usually wiring to dash from ECU plug.

Sometimes the plugs on dash side or ECU side have the wires falling out due to loom being tugged on by accident (common problem on Nissan's). Some put tape or similar around wires so plug has something to grip onto.

I think is 3 and half times more spark output with the truck LS coilpacks (with heat sinks), but puts more load on electrical system. I noticed one tuner on here has neatly mounted the coilpacks in head with short leads to sparkplugs (RB26), so looks nice. Just can't fit coilpack cover (maybe need to make custom coilpack cover with a hump in middle to protect coilpacks from water, dust, etc).