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Rb26 - Stock Afm Voltages

R31Nismoid

By R31Nismoid,
in Engines & Forced Induction

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R31Nismoid Grand Master

R31Nismoid

Posted
Posted

When someone has some time... can you please check what voltages yours is reading

@ 1000-1100 rpm when warm, with no throttle input

Ive got a bung AFM, however not sure which one :D

Im getting the below via PFC

AFM 1: 0.8~1.1v

AFM 2: 1.2~1.4v

So i'm trying to workout which one is fked before i go pulling it all apart and save myself the hassle of pulling the working one out first :D

Car stalls when i pull both out too which is odd and not helping me check which one is playing up as ive done it previous and the car idled fine without load like it should.

Could also be loom which will be check #2 after i get another AFM over the weekend

Cheers all.

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Duncan Grand Master

Duncan

Posted
Posted

I don't really understand. You said it stalls when you disconnect both (of course) but what if you disconnect just one?

generally if that doesn't tell you, give it a rev and the one that is slower to respond is the dying one.

R31Nismoid Grand Master

R31Nismoid

Posted
  • Author
Posted
I don't really understand. You said it stalls when you disconnect both (of course) but what if you disconnect just one?

generally if that doesn't tell you, give it a rev and the one that is slower to respond is the dying one.

Ye i disconnect one (or the other) and it dies too... pain in the ass thing as it didnt do that with the other AFM's in there so i dunno. I think its running that bad before i pull the AFM out (on cold start) that it stalls as its just getting the really wrong signal

hah, i just happened to have the workshop manual open at this time and skimming through it states that the voltages should be between 1-1.5v.. so does that mean the first one is out?

fk... thats the hardest one to get too :(

Although thats a fair gap in volts... suppose they gotta allow for everything

Thanks for checking :)

MrStabby Grand Master

MrStabby

Posted
Posted

Consult reports my ones at 0.9v and 1.1v - If you can log the output then that should tell you.

IIRC its supposed to run in a limp home mode if one of the AFMs is down (factory ECU, dunno about FC)

  • 2 months later...
joeleo87 Experienced

joeleo87

Posted
Posted (edited)

Hey nismoid just wondering on how you went with the voltages?

i thought my problem was related to my loom but i was wrong. Ive just replaced my bottom AFM with a spare i borrowed of a mate, but my voltages are different? im not sure what they were before though.

so at the moment they read

@ ~ 1400RPM (cold start idle)

AFM1 = 1.20 ~ 1.23v

AFM2 = 1.06 ~ 1.10v

AFM2 is the "good 1" (if there is even such a thing as a good AFM)

AFM1 is the 1 i've borrowed of a mate.

now clearly those readings are no where near each other? and this is a problem?

just curious the hear what some1 "good AFMs" are reading?

Edited by joeleo87
R31Nismoid Grand Master

R31Nismoid

Posted
  • Author
Posted

My loom has arrived @ Nissan, i haven't picked it up yet though so i cant confirm 100%

However if yours isn't dropping below 1.05-1.10 then that i think is ok, mine drops below 0.80-1.00v and hence sometimes the PFC is thinking the AFM had died when i dont thin it actually has.

I should have the loom replaced in a week or two. PM me then... ill probably forget the thread is here haha

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