M35 Afm Issues - I Want To Fix This Once And For All - Need Your Help

[Dane]

I have seen quite a number of threads on here with m35 owners who's AFM's die out of no where

Mine managed to die today after being replaced not too long ago by previous owner, contact cleaner did not help - limped the car to work.

I noticed while searching on here some people get genuine parts that last a few weeks and then die again....this is just rubbish!

I am familiar with these types of issues as the my99WRX/GT Forester has the same looking AFM (different part number 22680-AA310 as opposed to the nissans 22680-6N211 and now 22680-6N21A) The subaru ones would die extremely easily as well - as we all know different vehicles had different limitations, but with a power-FC on the my99 subaru you could run a z32 AFM which basically never die (so i'm told). You could run cheap chinese AFMS but they lasted even less and ran quite rich...

Anyway I got a call today from someone with a WRX regarding some parts i was enquiring about - he was telling me he had a resistor that tricks the car into thinking air mix is always optimal and never throws a code. he had the resistor in the plug !

Has anyone ever heard of this, is it dangerous to the engine or not really? I assume its about as dangerous as running a mafless tune?

I did some googling : found this http://hikickracing.blogspot.com.au/2010/11/tuning-rx-7-afm-resistor-trick.html

im sure there are more pages like this online... I'm far from an expert but would love to hear your opinions - looks like this guy on his RX7 did the resistor a in the actual AFM rather than on the plug to adjust mixtures

(EDIT: this rx7 link probably still requires a working AFM where as the guy with the WRX told me he didnt use one at all....this i am not sure on)

so - guys - will this sort of thing be an option for M35?

Edited January 8, 2014 by Dane

[PN-Mad]

Well for a start he is talking about a flapper door afm in the link, not a hot wire afm. I dunno if it could be applied to hot wire in the same way. Has the wrx guy done this?

I don't think its a good idea, and neither do I see how a resistor would solve the problem of failing afms.

But if you want to risk the consequences of getting it wrong, I'd be interested to see the results.

[Dane]

Well for a start he is talking about a flapper door afm in the link, not a hot wire afm. I dunno if it could be applied to hot wire in the same way. Has the wrx guy done this?

I don't think its a good idea, and neither do I see how a resistor would solve the problem of failing afms.

But if you want to risk the consequences of getting it wrong, I'd be interested to see the results.

Yeah - From what the WRX guy said he runs NO AFM with a resistor inside the afm plug which sounds weird but possible

And this resistor i found on t he rx7 is probably useless but got me wondering what we can do in the way of pro-longing the life of these AFM's or finding a solution to run our cars without them ,without the need to run aftermarket ECU and a re-tune.

[PN-Mad]

Well, you could try a heap of different afms on the dyno. There are certainly more reliable items out there, but that depends on how the voltage curves compare. Log it on the dyno to see if it's comparable and provides safe results. First would be a 350z/v35 item I should think.

But seeing the ecu needs some sort of input to calculate load and fueling, I wouldn't just replace it with a resistor.

[scotty nm35]

My aftermarket ones are lasting fine. Nissan and Subaru.

You could fit an Emanage Ultimate, then you could theoretically run any afm in the Greddy list. Or you could custom tune off any afm not in the list if your tuner is good enough.

The hassle with going MAP sensor is... the gearbox uses the afm signal to adjust the auto line pressures. So you still need to run one.

[Dane]

Thanks Scotty , Haydn said i should send you a message about sourcing new aftermarket AFMS but I cant send you PM's must be full.

How much can you get these aftermarket ones for and how long have they lasted in your car? whats the part number and the car intended for them ?

If they are cheap enough i might buy some and be done with it but to be honest if I have to spend heaps every few months on a sensor we need a better soloution!

there is so much difference in price of some of the aftermarket ones - ranging from 30-180 for non genuine- pretty crazy

I found a claimed "genuine" AFM for $175 PP

http://www.ebay.com.au/itm/180823121514?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

but If something like that is going to last a few months then id obviously prefer to have a few of these in the glove box : http://www.ebay.com.au/itm/331052494121?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649 (pending of course that one works)

Keen to hear about your aftermarket solution Scotty!

[scotty nm35]

My AFM's are fine, and have been in use in cars for well over a year. Sometimes they run a little richer than the OEM one, but it only seems to be on modified m35's which would be running rich anyway. I would say the top end on the air curve has a slightly higher voltage, but I would recommend tuning the car well before then regardless. Mine has been running perfectly for 6 months+ and flows 3 times the air a stock car would ingest.

I sell them for $65. PM me if you need one, I just cleared out my inbox.

[Dane]

pm sent.