Maf Adjustment

[paulmc]

Can we adjust our mafs to let unmetered air into the engine to control the air fuel ratio. As our cars run really rich it may be a quick fix for those not wanting to go the e-manage way

I do know all the dangers associated with doing this. Just a thought

[ako]

Yes you can, and it does make an immediate difference in terms of fuelling and fuel cut.

Theres a screw on the bottom of the MAF/AFM, theres a sorta wax stuff over it. Peel it off, and screw it out. Leans it out to something sensible, as poopsed to the unreadable 10:1 the things are normally at.

[paulmc]

sounds good to me. I will give it a try once I get home on Wednesday

cheers ako :thumbsup:

[ako]

Put it this way - it, in general, raises the fuel cut on most mitsis by about 3-4psi. MORE than enough to get you doing some serious times without having to hit the blue bottle.

[bradc]

blue bottle?????

[d3x]

Think he's talkin about nos

[AllBeItMine]

i didn't notice any difference on mine...

it was already half out. talking abotu an obstruction about half the size of a 5 cent piece...

let us know if it makes any difference for you though mate.

[paulmc]

i didn't notice any difference on mine...

it was already half out. talking abotu an obstruction about half the size of a 5 cent piece...

let us know if it makes any difference for you though mate.


Did you check the air/fuel ratio before and after.

What sort of screw is it?

[ako]

i didn't notice any difference on mine...

it was already half out. talking abotu an obstruction about half the size of a 5 cent piece...

let us know if it makes any difference for you though mate.

Every car I've done it to, its made a noticable difference. Raised the fuel cut on rhys's car by at least 3psi for one, ditto for my old vr4, actually, for anyones car who Ive seen do it..

[-LegnumVR4-]

Mines right out to the max at the moment, still tuning the E-Boost and haven't hit the cut yet.

U can put a little bit of glue or silcone on the thread to stop it unscrewing as its right on the end of thread when fully wound out. Or as Marky said to me, just turn it upside down and use an over sized screw driver in the hollow end to screw it in.

[Wodjno]

Mines right out to the max at the moment, still tuning the E-Boost and haven't hit the cut yet.

U can put a little bit of glue or silcone on the thread to stop it unscrewing as its right on the end of thread when fully wound out. Or as Marky said to me, just turn it upside down and use an over sized screw driver in the hollow end to screw it in.

Call me STUPID if you like , but looking at this screw i can't see that screwing it out a little or alot will let in anymore air .. Unless you take it right out .. ??

[ako]

Okay, here's how it works..

Look down your AFM/ MAF from the front. See how the meter itself is divided up into a couple of sections? The part at the top centre is all that is actually metered by the computer. It just has an assumed value for how much is going around it.

By screwing this screw out, it gives a bit more area for air to slip through, unmetered by the ECU. Not enough to cause damage, not by a long shot, but it is enough to a) let you get a bit more boost in there, and b) lean the mixtures out a bit so they begine to get close to something sensible.

Put it this way - I could screw mine out to get the thing running as its meant to, or screw it all the way in if I felt like popping a few flames on overrun. It actually does make a difference, and it wont kill the engine.

[AllBeItMine]

Every car I've done it to, its made a noticable difference. Raised the fuel cut on rhys's car by at least 3psi for one, ditto for my old vr4, actually, for anyones car who Ive seen do it..

yeap. say it again - didn't make a difference for me. i was still getting fuel cut and **** fuel ratios before and after. but hey - my car does have issues.

[venomboy]

sounds good , anybody got a picture?

[bradc]

flames you say....hmmm that is something I have to try!

[-LegnumVR4-]

Its easy to find. As the MAF sits bolted up to the airbox, unclip the box and undo the clamp that holds the MAF to the rubber intake pipe. Turn over the MAF and u'll see a cylinder shape on the underside with silcone in it. Use a small flat head screw driver and dig out the silcone (should come out easy). Once done u'll see the slots for a large phillps screw driver. Look inside the MAF and u'll see a small cylinder, unscrew this so the cylinder inside is flush with the inside of the MAF inner wall. U have to put a little bit of silcone/glue on the thread of the cylinder u unscrewed to stop it from falling out or turn it upside down and use a large over sized flat head screw driver and wedge it to the hollow end of the cylinder and screw it in so it has more thread, screw in till its flush.

What a mouth full :)

[Big Ian]

picture's are now added within the member's section clickHERE (http://www.clubvr4.com/forum/showthread.php?p=80712#post80712)
:chugchug:

[Ghost_2008]

Hi guys, I know it's an old thread but where's the pics gone? I can find them in them the corresponding article.... Pics would help as I have had a look but I could find the screw......

[psbarham]

Hi guys, I know it's an old thread but where's the pics gone? I can find them in them the corresponding article.... Pics would help as I have had a look but I could find the screw......

turn the maf upside down and you'll see a circle the size of a 10p on the bottom, the middle of that is a soft goo (technical name) pick that out and you'll see a large screw. wide that out a bit at a time and go from there

[Ghost_2008]

Ok I have found images of other maf's so I understand it a bit more..... The screw is on the underside of the air intake pipe which is afixed (and integral) to the MAF (box shaped item behind the air intake)...... So it' on my list of things to do tomorrow/Saturday.... I fitted a new K&N filter today, the oem filter was filthy......

But where's the picci's gone?

[swinks]

From my experience, undoing screw is leaning mixture in fact. May help if you have overfuelling issues with cone, mushroom, etc. filters
But no help in moving fuel cut at all. Before and after I still have fuel cut at 0.9 bar.

[Turbo_Steve]

Swinks....if it's leaning the mixture, the ECU is seeing less load. If the ECU is seeing less load.........it's further away from fuel cut :D


Chances are it's only by a smidge, though.

[swinks]

Steve, it is leaner according to wideband gauge. And, yes, agree with you that it should interfere with fuel cut, but in reality there was no difference regarding fuel cut.
It's my guess, that fuel cut doesn't depend on ecu cell loads only. Must be other factor.

[Turbo_Steve]

Indeed, time at load is an additional factor, so whilst it's reading a different load cell, it may still be too high.

Probably worth reducing boost target very very finely with it out until no cut, then wind it in, and see if it can be increased by a tiny amount.

[swinks]

Well, next time visit in Eurospec, gonna ask Ben for some extra time and play with MAF settings. But if there's any difference it must be like 0.01 to 0.03 bar. Not sure if it's worth to play with unmeasured air.

[Turbo_Steve]

You're probably correct, there, Swinks. But it will be nice to know, either way, and any improvement in fuel usage on a VR4 is a worthwhile investment :D

[MarkSanne]

Just done this mod and added pictures in the original thread @ http://www.clubvr4.com/forum/showpost.php?p=520247&postcount=71

[Ghost_2008]

I managed to do this mod this afternoon..... still to see if I notice any benefits, but I am hoping that this mod with a new K&N filter should improve my fuel consumption..... the OEM filter was almost black......

Does anyone know why they have this screw on the bottom anyway, it looks fairly redundent if you ask me?

[WizardKing]

I have just done this mod too !

I took the screw out and turned it round to give a bit of a smoother air path. Finished it with a dollop of silicone, to keep it in place.

Should there be any noticeable improvements, I'll report back.

[aboo]

I'v just seen this & going to try it tomorrow. I will report back with results.

[Adam.Findlay]

did it back to my car yesterday. havnt noticed a power increase as such, but i wicked up the boost a touch and felt the timing being pulled so i will leave it alone until i get a uprated FMIC and then see how far I can push the boost before cut kicks in. without the adjustment done and stock FMIC I could borderline pull 14psi without it cutting.

[paulg23]

Did the MAF mod on my otherwise standard car yesterday. It is definately different to drive. Seems just the same when cold though. Not as 'lively' when hot. Fuel consumption was, at a guess, below 20mpg. Hopefully that will improve a bit. Will know next week.

[WizardKing]

Initial observations seem to indicate more grunt !

[Adam.Findlay]

after driving for a while. it does seem to pull that little bit harder. not much but a little bit.

[swinks]

Have some comparison with mod and different filters, especially today after journey to Donington, here:
1. Mod undone + panel filter = let's say feels stock and runs standard :p
2. Mod undone + BMC CDA filter = feels lazy (turbo lag effect) and overfuelling
3. Mod done + panel filter = feels bit better response and running noticable leaner (wideband gauge)
4. Mod done + BMC CDA = feels indeed better response and sound (low revs range like doubled torque) and runs leaner but not such much like panel
So, now I have option 4. Runs sweet. :D

Regarding boost and fuel cut: well, as expected there's no noticeable difference. Had set boost at 0.85 bar. Holds nicely. So no drop in boost, I didn't push car to the limits (checking boost and fuel cut) because wasn't sure how much lean I'm running. Didn't want do big bang in my engine. :upsidedow

[psbarham]

what set up was it running on the way back from donny? there wasn't a lot of smoke when you booted it so i doubt there is too much over fuelling

[swinks]

No 4.
I didn't boot to the floor, something 80% throttle. Still not sure of afr under heavy load. Didn't want find myself in Eric shoes :coat
In my plans is visit to Eurospec to check it out.

[psbarham]

No 4.
I didn't boot to the floor, something 80% throttle. Still not sure of afr under heavy load. Didn't want find myself in Eric shoes :coat
In my plans is visit to Eurospec to check it out.

explains why i had to back off to save hitting the back of you /lol

very little smoke though, the only bit i saw was a quick puff when you shut off at the top of the hill, but no strong petrol smells so it can't be that rich. fair point on checking the afr's though, better safe than sorry