I am sure this has been asked a bunch of times by now.. but I cant find a thread on it... call me stupid and link me if I missed it

Can an s5 meter be used in an s4?

if not... is there a way to repair the door spring tension in the s4 meter? I believe this to be the source of all my weird engine surges...

I dont want to upgrade the meter because I want to install a stand alone system ... so I dont want to spend the money on a megasquirt or anything like that... should i just replace it... or is it possible to fix it?

 

No, s5 use maf sensors, not afm's you can't

 

Actually, I think you can, but the plugs and wiring are different, so you would have to do a little "re-wire" job to get your inputs & outputs that you'd want...

Do a search- I've seen this somewhere (how to rewire 'em)

 

if i find it maybe i will write up a faq while i do it
thanks... i will search more

but what about fixxing the current one

 

The temperature sensors are the same, but the flow meter resistance values and wiring are different.

Why not just replace the spring? Even better, you could replace the whole AFM, as I'm sure that somebody on this forum has converted to a standalone EMS and doesn't need their S4 AFM anymore. Geez, I think my friend just unloaded some at the local dump today.

The S5 also uses an AFM, but it looks just like a MAF sensor from the outside just to confuse everybody.

Also, a MAF sensor is technically an AFM.

 

Yea, I thought it was the same thing? just different terminology...

air flow meter
Mass Air Flow

same thing

But yea the S5 MAF is like twice as small as the S4 one! I like it alot better becuase its just looks better than having this big metal box like the S4 hanging off your TB.

 

AFM and MAF are not the same technically.

 

The short answer is yes but there are zero gains. Don't waste your time.

Why do you think that?

 

I think the gain is a small nicer looking maf. The one on my S4 is pretty big and bulky. Too bad you couldn't just rip out the sensor and plate and make your own MAF cabinent with a bigger plate or something that allowed more air in..

 

this might sound silly.. but i have bene thinking maybe look into a lexuz v8 (1uz) afm.. they are the same lay out and are bigger i am not sure bout the plug though

 

The ECU was programmed for the size and flow of the stock MAF sensor. If you change the sensor the ECU will not accurately measure air and the engine will not run properly. You would lean the engine out and possibly lead to detination.

 

The Lexus uses a hot-wire AFM. It won't work without extra electronics.

 

Airflow meters sense the mass airflow. Unlike most of the older airflow meters that used an array of sensors, the hot wire type uses only one sensor, so it has gradually become known as a "MAF sensor. However, a MAF sensor is a type of airflow meter, and airflow meters sense the mass airflow, so the whole thing is rather confusing. I wish the industry would have just kept calling it a "Hot Wire" AFM just to keep things simple. It would be like if Ford made a car model called a "CAR", but you could still buy a car from another dealer, which would technically be a car but not a CAR, even though the CAR is a car.

It may help to look at the bigger picture:

There are 3 common types of electronic fuel injection (EFI):
1) Mass Air Flow - Primarily uses an Airflow Meter - Stock on FC RX-7's. There are 3 common types of airflow meters:
a) Vane type (The S-5 AFM is a linear variation of the vane type AFM).
b) MAF sensor (Hot Wire)
c) Vortex flow sensor (Karman).
http://www.stealth316.com/misc/toyot...ow_sensors.pdf
2) Speed Density - Primarily uses Tachometer and Manifold Absolute Pressure (MAP) sensor - Used by most people who convert to a standalone EMS like Haltech, Microtech, Wolf, etc.
3) Alpha-N - Primarily uses Tachometer and Throttle Position Sensor (TPS)

Good point. Before tearing apart the AFM, it is probably better to check the BAC valve, and to look for vacuum leaks in the intake system.

 

I have been looking for vac leaks and such for over a week now... I am pretty much forced to say that the AFM is the problem being that when my car idles (well as close as it gets to an idle, bouncing 1-1.5k rpm) the voltage readout is 1.1 - 1.2
I have tested most of my other sensors too... calibrated my tps ect ect... there is a whole thread on that problem kicking around here somewhere.

so if I were to change the spring... how would i be sure that the spring is the right tension? where would i get a proper spring? or would it be better to just change the whole sensor?

 

naw man its the tps. I posted this a couple days ago on how to test it easy without a voltmeter. Just read it.

 

1.1 to 1.2 does sound a little low for a 1-1.5K idle, I get numbers close to that at a 75mph cruise, so you may just be right about a weak spring...

You should see something around 3v at a 750 idle, and 4 v with key on...

 

I get the 4 v with the key on. then I start it and it goes nuts.. I really do think that it is my problem... I just need to get a known working one in there to be sure

Does anyone have an S4 air meter they dont need?

 

OK, it looks like you might have nailed it, then...

At this point, why don't you break in to that sucker and see if the spring broke, or somehow "unsprung" itself? Got nothing to lose if you're in the market for another one...And if you do happen to get her "tightened up" and working again, let us know how it went, this might help a lot of guys...

 

well its 11:45pm and I have nothing to do.. so maybe I will just go do that..

also the fact that my wide open running isnt affected at all by it ... that also seems to point in that direction..

 

so as I am looking at the meter I see how to add tention to the spring... what would be the proper way to calibrate this spring.. or an easy way to get it close for that fact

P.S. The egineer that designed this lil guy I want to pat on the back... its simple and effective

 

I've never had to bust in to mine (yet), but I've played with many things with springs on them, and if I wanted to tweak it to exert more force, I would find a way to "add a revolution" to a circular spring, so that it's coiled tighter, or just bend any other type that's not a coil.

Somebody was talking about having to do this, but I can't remember who...Hailers, maybe?

 

Ok so I was playing with calibrating the AFM (as I devised a way to do so... I will post that soon) I cant get the voltage above 2.1 as it stalls my car... The idle starts to even out as I do get closer to desired voltage though... any ideas on the stalling?

 

Why are you doing this when an AFC does this more effectively without any possible chance of damage to the unit???


-Ted

 

I am doing it because I want my car to run properly... and I am going to put in a stand alone unit shortly... so why bother wasting money on things that I will just be ditching later.. besides its not like its broken... just out of adjustment

 

So where are you getting all these voltages from?
Are they from Mazda?


-Ted