R32 Gtr Revs Drop, No Power, Spluttering, Dies.

[joeleo87]

I bought my GTR about 3 weeks ago, first week no problems at all...it all started when i changed the panel filter. first the car revs dropped off while i was driving and the accelerator was non-responsive. and it went down hill from there, the cars idle was sporatic, sometimes the revs would drop and cut out completely while i was driving (but start fine again after???). sometimes the car would start but it would splutter and struggle to keep the revs up.when that happened i was suspicious of the AFMs so i tapped the top AFM and the car stalled straight away. Beauty i thought ill change the AFM over. i borrowed an AFM of a mate to test it out. changed it over 4 days ago and thought the problem was solved until today on the way to work its died while i was driving it....

car is completely stock apart from cat back zaust and a mines ECU.

a few questions:

is this an AFM issue?

could it be caused by anything else?

this problem is doing my head in!

cheers

[LotusGTR]

Sounds very similar to n AFM issue I had. I replaced the AFM and all was OK again......Probably not much help to you as you've sort of tried that.

[joeleo87]

Mechanics cant help me, unless the car cuts out when they drive it..... Murphys law, it never happens.... i took it to the mechanics they drove it for about an hour nothing happened but it shits itself on the way home.... i need to know is this just an AFM problem? Could anything else cause such behaviour? Fuel issue? ECU?

i cant drive my car until this is fixed! im on the Ropes so to speak.

[LotusGTR]

I got my mechanic to drive it home, keep it over night and then drive to work. I guess you've got to trust your mechanic.

[R31Nismoid]

Sounds like AFM's again, or the wires near it.

If you used 2nd hand AFM's then its highly possible the new (old) AFM is also playing up

[joeleo87]

so 100% AFM nismoid?

When i had my old AFM on there it was dying after about 30 mins of driving. but now with the "newer/older" AFM its back to the start of the timeline (just stalling occationally).

it seems in every case of a vaulty AFM, its always the top 1? too much vibration?

maybe i cant try and source some new plugs or something? is there any way of testing it?

also i was thinking maybe i should get 2 x Z32 AFMs that way ill know they arent 20 yrs old? but then ill need a retune?

[R31Nismoid]

Well not 100%, im just saying it could be another dead one, its highly possible.

Just buy some NEW Z32 or NEW Nismo AFM's. Then you dont need to worry about it for another 10 years

And yes, you need a retune

[Burgerman]

when I first got my GTR it had a "mines" ECU. I had it checked out and it was a faulty standard ECU with a mines sticker on the side. It was causing the engine to run too rich and causing the spark plugs to foul up. This would characterise itself in the form of the engine cutting out, small to medium size plooms of black/brown smoke (unburnt fuel) out the exhaust and on ocassion complete stalls. Unbeknown to me I tried to have the standard ECU remapped but it was at this point after hours on the dyno I found out from another mechanic that the ECU was actually faulty and causing all sorts of missfire issues. Problem solved when I had the PFC fitted and tuned the AFM's were fine.

not saying it's definately the ECU but if after you swap over both AFM's you are getting the same/similar problems you might need to look at the ECU after say spark plugs, and check coil packs etc.

Cheers

PS: R31nismoid did you get my pm?

[joeleo87]

yeh right ill take that into consideration. im going to get the AFM reconditioned as i dont ahve a spare $600 laying around for new AFMs + tune.

I bought the car from a mate and he was driving it every week doing 400kms per week and never had any troubles. He said the car has better fuel economy then his 260 stag, so i dont think it could be the ECU but ill keep it in mind

cheers

[R32 Driver]

could be AFM, CAS, Ignition module, coil packs?

[joeleo87]

well im sending my AFMs off to get reconditioned tomorrow should ahve them back for the weekend.... hopefully it solves the problem if not...... i dont even want to think about that lol.

[LotusGTR]

If not mate, you can buy my std ECU from me and give that a go. Let me know if that's a road you want to go down.

[joeleo87]

Had my CAS and ignition module bench tested and they are fine.

plus reconditioned AFMs

what else is left? Fuel pump and ECU?

just to clarify though. if the fuel pump has shit all pressure would this throw the CAS off??? because when i died 1 night i called the RAA and he did the light bulb thingy on an injector plug and said the CAS must be damaged because there was no pulse BUT i had the CAS bench tested and it is fine???

cheers

[joeleo87]

I had my auto else test my fuel pressure and it came back fine. So the only thing that is left is the ECU? i really need some help here im not getting any answers from mechanics. the problem never occurs when its in the shop or when they take it for drives.....

Tonight when it cut out i noticed the taco needle spazzed out something cronic just before it died, moving heaps fast between 0 and 2 thousand RPMs.

id start the car and the taco would spaz out. It started everytime though just didnt last long (spluttering).

after 10mins

Then it would start fine, idle nicely for about 15 seconds then run rough then cut out...

another 20 mins

then its was fine for the drive home

If i could find a Power FC to borrow to test sensors it may help but i dont think they will show faults while the problem only surfaces at the most inconvenient times sad.gif

any1 else got any ideas?

appreciate the input

cheers