AFM problems - I think?

[caminperth]

Hey guys - got a problem to report - wondering if anyone can help out.

Last night me thinks - it's cold, 0.9 bar is going to be waaay safe so I dial it in and plant it in fourth. At this point a few things happened - which have happened before:

first boost comes up - ok, all good

then suddenly everything cuts completely for about half a sec - felt like I'd turned the key off!

then it cuts back in...

then it misfires around 5000rpm - which I'm guessing is the plugs and I'm hopefully going to fix that problem today...

the first problem of the engine/revs cut I'm thinking is the AFM going past it's voltage limit and shutting down.. does this sound right? what can I do to fix it? I've sprayed/cleaned it with heaps and heaps of electrical cleaner which didn't seem to make much difference..

Any ideas?

[G0DF4Th3R]

why do u think its the AFM? wouldnt it be like a fuel cut? coz u put it at 0.9 and then boost spiked higher and then it cuts? ure using a bleed valve or EBC?

sorry i dun wake up before 12AM so this probably wasnt an intelligent answer

[zanda]

cam says - "i'm running a evc.. i'm thinking it couldn't be boost cut because the std controller isn't plugged in so the comp wouldn't know what boost the car is running.."

[SHUTO-BOY]

sounds like a speed cut? i guess ure sticking it pretty hard on 4th right? but thats not right,u have a pivot speed meter..hmm

time to bring it on the dyno mate

[Cake]

speed cut is soft

it isn't a hard cut that'll cut everything off.. the revs just hover at the same spot and car won't go any faster... must be something else

u running 0.9bar , u still got stock intercooler right?

[G0DF4Th3R]

anywayz, stuff it man

its time to get the GTR u looked at on Friday

[APA]

cam, sounds like faulty airflow meter

adrian

[G0DF4Th3R]

yeah to fix it is relatively cheap

just buy a Type-R rearview mirror

Adrian sells them

[APA]

stop whoring bitch hahahahaha

ur gonna force me to ditch my type-r mirror umm howabout no it lets me see more off the road

go back to digging up those old skool threads bambam (aka The Fonz)

adrian

[G0DF4Th3R]

lol

yeah u need that HUGE mirror to see how many ppl your holding up

hahahah

[NO_RSPECT]

hahaha what a classic

hey cam if you want to take my AFM tomorrow and go for a fang on tonkin to see if yours is stuffed thats fine mate,

lemme know

RiaZ

[DanielGTST]

Caminperth,

I had the same thing happen to me when I had my car at about 13psi while mucking around. It was fine on the dyno but as soon as it was on the road it would start to have the problem you described.

The guy told me that it would be even worse on a colder day due to the fact that there was too much air getting into the engine and the air/fuel ratios where not adjusting correctly on my stock ecu.

A SAFC would probably fix your problem, I have a simple Pivot air/fuel meter (1 universal setting) and adjusted it to make it a little bit leaner and it has fixed the problem for me.

I am no mechanic/tuner so it is just a suggestion

Daniel

[caminperth]

aidwin - as you said man - it's not the speed cut..

b005t - yea - i know what the speed cut is like and this ain't it. and yea - am still running stock cooler...

adrian - could be - but it's fully intermitent..

bam - i wish i could afford the gtr!

daniel - i've got an afc and itc (old skool apexi fuel and ignition controllers) and that should sort out the fuel issuses at higher boost...

i fixed up the plug issue today - tho can't really try it out in this weather..

still at a loss as to what it could be.. still got an inkling it's the airflow meter maxing out... will do it more when there's cold weather due to more air due to the density change... sound right?

[caminperth]

oh yea - thanks for the offer riaz, but cause it's not happening all the time i'm not sure how i'll tell the difference...

anyone know where you can get a better afm that will talk to the stock ecu?

[G0DF4Th3R]

get the Z32 AFMs then upgrade to the SAFC2

[caminperth]

hmmm... i think a cooler is on the cards first bam..

[APA]

cam still interested in the cooler? mine should be arriving any day this week

adrian

[G0DF4Th3R]

like what Riaz said:

check the weather reports and when theres a cool night (which is every night - dumbas bambam) just call me up and i'll swap AFMs with you to help pinpoint the offer.

bambam

[GTS-t VSPEC]

Cam,

It's the boost cut/fuel cut. The boost controller has nothing to do with it, it's the AFM that tells the computer when it senses too much air flowing, which means too much boost, and it will hit boost cut, resulting in a nasty sudden halt to the car:D

You'll need to replace your ECU or get a fuel cut defender to stop this happening. It is worsened by the fact you have a stock cooler, and cold air is denser, thereby the AFM senses more air flowing:D

Hope that made sense (and is true)

[G0DF4Th3R]

hahahah see BAMBAM was right