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M35 Afm Troubles

m35stagea

By m35stagea,
in Four Door Family & Wagoneers

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Daleo
Daleo

Speaking from my experience; a brand new Nissan one at $270 lasted almost 3 weeks. I'm not the only one to have the same experience. No warranty, and they laugh all the way to the bank. I bought a ge

scotty nm35
scotty nm35

Fit an Emanage, then you can probably go a Z32 or VQ35 afm and never have an issue again.

Daleo
Daleo

I'd be willing to bet the Maxi-Rom could probably be scaled to cope with the change as well.

Posted Images

BoostdR Mentor

BoostdR

Posted
Posted (edited)

So anyway. I have a theory on all these blown MAF's. When the plug is wiggled it goes 0-5v pretty quickly which Im sure stresses the sensor somewhat. My AFM is mounted with the plug up which looks to be rubbing on the bonnet. From what Google tells me the plug should face to the passenger side not up or towards the engine. Away from heat and away from vibration and no bonnet contact....

Edited by BoostdR
BoostdR Mentor

BoostdR

Posted
Posted

post-49288-14446407647774_thumb.jpgpost-49288-14446407832724_thumb.jpg

Now that I have a working MAF I was able to plot the MAF VS MAP/emu output to adjust my emulation airflow meter output table and continue to run solely off the greddy MAP sensor.

I found that the MAF sensor either has some rate of change logic built in for acceleration enrichment or the BOV return causes an initial spike as seen in the logs when the throttle is stabbed. Either way I found adding substantial acceleration enrichment took out all dead spots.

The intake and water temp has to be wired totally separate to the oem sensors as the EMU loads the signal which skews the OEM values by approx 20degrees . Once I've installed some I'll upload some temperature fueling adjustment parameters.

Matt

  • 1 month later...
conan7772 Mentor

conan7772

Posted
Posted

The wire isn't the issue, the afm has an ecu inside it which fails. Could be low input voltage causing it, but I have seen a brand new Nissan afm blow the first time the car was booted, so it definitely isn't dirt or oil causing that fault. The hotwire isnt able to be touched in these really.

The original superseded OEM part number is the one to get, they last many years, it's the new Nissan part number that fails constantly. If only there was a batch of old stock laying around. Until then we are stuck trialling aftermarket afms till we find another good source.

I've been searching for answers on why there are so many blown afms.

An article on WRXs mentioned excessive vibration as the proven culprit.

Aftermarket intakes are generally all alloy transferring more vibration and shudder back to the afm.

I guess that's why the upper half of the stock intake is rubber.

I have an AMPerformance intake to shortly fit, and will try to mate the bottom half only with the stock top half.

karter Enthusiast

karter

Posted
Posted

I've done about 20,000k on one of Scott's replacement AFMs - it runs a little richer (8k per litre vs 8.2 on the original) but I've had no issues (I have two spares in the car just in case - that should guarantee that it will last forever). The car is not modified (2001 ARX).

conan7772 Mentor

conan7772

Posted
Posted (edited)

Yep sure, not dismissing any possibilities, just thought it was worth mentioning.

All parts have a life span, however it appears to be a more common problem with modified intakes.

The fact that you have two spares is my point. It shouldn't be necessary.

I found that info on a 2004 discussion where someone was testing them on various intakes in WRXs.

Hard pipe intakes and vibration was their conclusion for all the failures.

Just something to consider, if they are that fragile, even changing out your air filter with a heavy hand could damage it.

Maybe it could be as simple as adding some brackets to the afm mount or air box.

Mine moves around heaps.

Worth experimenting with don't you think

Edited by conan7772
Daleo Grand Master

Daleo

Posted
Posted

Yep sure, not dismissing any possibilities, just thought it was worth mentioning.

All parts have a life span, however it appears to be a more common problem with modified intakes.

The fact that you have two spares is my point. It shouldn't be necessary.

I found that info on a 2004 discussion where someone was testing them on various intakes in WRXs.

Hard pipe intakes and vibration was their conclusion for all the failures.

Just something to consider, if they are that fragile, even changing out your air filter with a heavy hand could damage it.

Maybe it could be as simple as adding some brackets to the afm mount or air box.

Mine moves around heaps.

Worth experimenting with don't you think

I had a brand new Nissan one fail within 2 months on a stock intake; and an aftermarket one lasted more than 2 years on a modified intake.

My airbox is very firmly mounted; so whilst not discounting your theory, I think it's a bit of a red herring.

People have postulated that using oiled cotton air filters will guarantee failure; I've had no issue even after extended periods using them, and i know of plenty of AFM failures using OEM style paper filters.

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scotty nm35 Grand Master

scotty nm35

Posted
Posted

Exactly Dale, they just seem prone to failure at top end flow. I have seen a genuine Nissan AFM last 20 minutes, first time he put the boot in it blew. No warranty either, as I couldn't prove the Km it had done, wasn't installed by their techs, and lastly was fitted on an import.

Got to love all these ways companies wriggle out of warranties.

BoostdR Mentor

BoostdR

Posted
Posted (edited)

When running the emanage ultimate you can use any sensor you like as long as the wiring is the same. Or even if it's not the IAT can be reused from the old MAF. It just goes between the green wire with black trace and the center wire..black with red trace I think it is. Or you can just go MAFLESS like I have done. I've been through 3 AFM's in 3months.

Nistune sell a HPX MAF that will stay in resolution. I might look at this myself as the MAP is a bit noisy on boost.

On the EMU the Airflow output map can do your load cut removal and calibration for the OEM AFM load points.

On the EMU I/J and ING maps reference the Airflow Hot wire Voltage for X axis load and adjust the scaling to suit

Edited by BoostdR
scotty nm35 Grand Master

scotty nm35

Posted
Posted

When running the emanage ultimate you can use any sensor you like as long as the wiring is the same.

You assume most of us are running the EMU, but there are probably only 30 Stagea's powered up on aftermarket computers in total I suspect, some of which run the fcon and HDI.

The HDI has little chance, doesn't have injector or coil interception and modifying the AFM signal isn't the way to tune cars at the best of times imo (certainly not for high boost, think modern Apexi safc). The Fcon works better in MAP tune than the EMU ever did as an AFM/MAP tune but if you think the EMU was hard to sort out... The Fcon is a whole other league.

The Link Fury will be 10 times better and should finally be able to ditch the AFM all together, plus it just started Ricks engine for the first time. Off to the tuners. :)

conan7772 Mentor

conan7772

Posted
Posted (edited)

So looking at Nistune AFMs, they're horsepower rated. See the drop down list in upgrading your maf options on Nistune website.( Nistune MAF Technical Notes) The various cars are listed with max horsepower. I'm assuming our AFM is 330 hp. So if you do install a Nistune HPX AFM , do you need the Nistune daughter board and software to calibrate it ? Or can the E-Manage do it. There are several models of the HPX that need scaling down...

Oh and it says hard pipe intakes are better than soft pipe, so there goes my vibration theory !

Wasn't my theory anyway remember. Haha

Need to sort this AFM issue out.

I want 400hp at the crank and a trouble free car.

This is an important thread, gotta keep it alive .

Edited by conan7772
Brick Mentor

Brick

Posted
Posted

So looking at Nistune AFMs, they're horsepower rated. See the drop down list in upgrading your maf options on Nistune website.( Nistune MAF Technical Notes) The various cars are listed with max horsepower. I'm assuming our AFM is 330 hp. So if you do install a Nistune HPX AFM , do you need the Nistune daughter board and software to calibrate it ? Or can the E-Manage do it. There are several models of the HPX that need scaling down...

Oh and it says hard pipe intakes are better than soft pipe, so there goes my vibration theory !

Wasn't my theory anyway remember. Haha

Need to sort this AFM issue out.

I want 400hp at the crank and a trouble free car.

This is an important thread, gotta keep it alive .

Nistune doesn't work on m35 mate
BoostdR Mentor

BoostdR

Posted
Posted (edited)

You assume most of us are running the EMU, but there are probably only 30 Stagea's powered up on aftermarket computers in total I suspect, some of which run the fcon and HDI.

The HDI has little chance, doesn't have injector or coil interception and modifying the AFM signal isn't the way to tune cars at the best of times imo (certainly not for high boost, think modern Apexi safc). The Fcon works better in MAP tune than the EMU ever did as an AFM/MAP tune but if you think the EMU was hard to sort out... The Fcon is a whole other league.

The Link Fury will be 10 times better and should finally be able to ditch the AFM all together, plus it just started Ricks engine for the first time. Off to the tuners. :)

I didn't assume most are running an EMU at all, not

sure where you got that from. I just stated another AFM can be used with an EMU as it can be scaled. I'm pretty happy with my $200 EMU thanks ;-)

Edited by BoostdR
scotty nm35 Grand Master

scotty nm35

Posted
Posted

Fair enough. Rescaling it may keep the EMU happy but the gearbox won't like it at all I suspect, even if you can work out the wiring.

I guess if I paid 2k for my Stag I wouldn't care much either. Just sounds like you want to watch the thing die a quick death to me... Don't say I didn't warn you.

BoostdR Mentor

BoostdR

Posted
Posted

The gear box will only get the output signal you give it so no worse. The scaling works on the X axis of the IJ and IGN Maps. Plus did you know you can run 4.91v output up to 6500 and 5v at 6600 without hitting load cut. Helps the box out

A quick death...more assumptions there mate.

If we are stating facts. The only limiting factors I found with the EMU are:

Increased shift flare due to getting around load cut( any piggy back)

Inability to adjust injector timing

Injector scaling and lag time correction formula is creative(putting a lag time under the OEM size field causes hot start problems)

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Facts are I have blown a few boxes, even once built. If you plan to run 35psi you will quickly be in the same boat (I assume again), especially on the EMU. Been there done that, all I can say is good luck with it, not trying to rain on your parade.

Timing drift is likely why you are now pushing coolant too, but hey, what do I know...

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