Rb25 Not Revving

[smokem31]

Hey people

I have got the rb25Det I put into my 31 running with everything connected including vct, afm, cooler... And it won't rev above 2400.....

I read it's most likely afm or tps... How can I check these?

It sounds like it's hitting a rev limiter.... Just before boost....

Any ideas?

Thanks

[wlspn]

Ok, well its in failsafe which is why it has a 2500ish rpm rev-limit...

Perform self diagnostic (will be a thread in DIY section if you don't know how) & check for codes.

If you have none try wiggling AFM plug & revving car to see if it suddenly revs higher.

If not try same with TPS. Did you do your own wiring conversion?

[smokem31]

Ok... I did do all the wiring... And double checked it all... I found the self diagnosis part, but my ecu has no LEDs, and no dash light cos it's in a r31.... Any ideas how to get a read out?

[wlspn]

With no ECU LEDs & no dash light not really... Maybe a light can be hooked up directly?

Like use a pin-out to find which wire is check engine light & maybe it can be wired to a light/LED.

No idea if it would work but only thing I can think of...

[kewp]

limp mode, check the afm and wiring

[smokem31]

hey people,

i have changed the AFM it fixed the limp mode problem straight away....

i have another problem though....

the engine is missing.

i though bad fuel at the start, cos its been sitting in the garage for about 2 months, on very low fuel, so i drove to the petrol station, added octane booster as well as premium, and let it run for a while. still missing on the way home, as soon as i pulled into the garage, it stopped missing, and was running sweet. so jumped back in to take it for a proper test drive, and it started missing straight away.

i have a 044 fuel pump and surge tank, and the pump makes some funny noises like its sucking in air, but surge tank is full... i have never run an 044 before so i am unsure whether noises are standard or pump is fu#ked.

i have changed plugs to NGK BKR5EIX-11

if i fiddle with the CAS and turn it completely anticlockwise, it sounds a tiny bit better....

also, when i back off throttle, the car almost stalls, sometimes does stall.

revs around 900 at idle

just trying to give as much detail as possible....

cheers people

[MBS206]

Misses when?

under load, all the time?

Can you narrow it down to a cylinder (Removing injector/coilpack) until car keeps running the same when you unplug one.

[wlspn]

Did you change plugs before or after replacing AFM?

If you done plugs, were in failsafe, then replaced AFM & now have a miss maybe you have just fouled plugs...

Car runs very rich in failsafe & for free worth cleaning & refitting plugs

[smokem31]

it misses at idle and under load.....

plugs were changed before AFM was changed....

ill try narrow it down to a certain cylinder tomorrow, and take plugs out to see if fouled.....

car is running very rich at the moment, but probably cos one cylinder not firing?

it really cant be anything else besides coil pack or plugs can it?

cheers

[smokem31]

hey again

ok, its cylinder 3 from the front of the block thats not firing.

when i unplug the coil pack, engine keeps missing just the same, if i unplug any of the others, it runs worse....

i swapped the coil pack with number 1, and still number three not working.

spark plug not firing.... so i swapped the plug with a new one, and still no go.....

oh, also, running pfr5g-11 plugs.

any ideas?

[wlspn]

Thoroughly check your coilpack loom. If possible remove that section of loom (connects just behind head, maybe half a foot after cylinder 6 coilpack.

Then test the resistance/continuity of all wires from loom connector to coil plug. If 3 is dramatically different from the others I would hazard a guess you have a broken or damaged wire, etc Someone else may know of a more common problem but first thing I would check...

[smokem31]

ok, ill check that, thanks.....

also, just checked, and plug does get constant 12v when ignition is on.......

what are the other two wires? earth? and what else?

cheers

[smokem31]

i want to test the signal wire from ecu to coilpack by probing with a test light.... just want to know if i need to use an LED light, or is a conventional test light sufficient?

cheers

[smokem31]

i checked resistance in coil pack wiring, and coild pack wiring is ok. so my problem is between the coil pack plug on engine loom, and the ECU.

as a easier fix, can i piggy back the earth wire from the other coil pack that fires at the same time as cylinder 3? or will this present problems at high revs?

cheers

[smokem31]

please guys, i am desperate for help!

i dont know what is going on with my car.....

cylinder 3 is not firing at all. there is continuity in all wires to the coil pack loom from all plugs.

after testing wires, i determined that coil packs turn on via the earth connection in the plug....

the only way i can get cylinder 3 to spark is if i piggy back the earth wire from another coilpack onto the earth wire to cylinder 3 coil pack, but i am thinking none of the cylinders fire together cos it still misses.....

its not a faulty coil pack or spark plug.

it cant be injector related cos spark plug is wet when i pull it out

does any other cylinder fire at the same time as cylinder 3 from the front of the engine?

does anyone know the pin out on the ECU for cylinder 3 coil pack so i can trace continuity to ECU???

i HAVE SEARCHED AND SEARCHED, BUT NO ONE I CAN FIND HAS THIS PROBLEM....

what is going on?

[Pal]

is it S1 motor or s2, check igniter amplifier if s1, at end of coil pack loom. may have one track burnt out

[smokem31]

series 2 buddy

[Pal]

http://www.scribd.com/doc/6654050/Nissan-S...3-Engine-Manual

have a look through this

[smokem31]

thanks....

i just checked continuity to ECU from coil packs, and they are all the same.... WTF?

how does one cylinder not fire when 12v, earth and ECU connections are all there?

[smokem31]

just wanted to finish up this tread for anyone else who has teh same problem in the future....

problem was injector not firing, and as a fail safe, the ECU will not give signal to coil pack to spark if injector is not firing to prevent leaning out...

cheers