Kamatari

its alright im grateful for the bits of help you're giving me now

i'll have a look connecting to the trailing coil seeing as the revs dont match up

Just wish the car work with it connected and can finish this...nothings ever simple :p

Kamatari

Havent had a chance to check the wire yet but any ideas what the voltages should be on the airflow with the engine off?

been trying to read and find out and its looking like it should be about 4.5v with the key set to ON and something like 2.5v at idle but if this is right mine is reading 1.5v Set to on and about 2.1v on idle..

HAILERS2

The volages for Turbo and NOn Turbo can be found in the free online FSM on this site in the FUEL AND EMISSIONS section of those manuals, sub section CONTROL UNIT.

See jpgs attached.

I was kinda trying to keep this thread alive for you til someone with a SAFC came along and piped in but.............................their a quiet bunch out there.

That rpm problem is odd. I don't know what to make of that. Might try that Y/L wire but that really shouldn't make a difference if the dwg is right. Then again it cost nothing but a bit of time to try it.

I really would try moving the internal cone of the AFM aft while watching the SAFC on ETC (watching the afm signal there to go down as the cone moves aft). Engine off key ON. IF working by yourself you could move it and stick something in there to hold it in postion while you go back and look at the SAFC reading.

Kamatari

its fine, its helping me find out more about my car as its all pretty new to me :P

going by what those voltages are saying in those jpgs, im hoping that im on the wrong wire as if im only reading 1.5v with it set to ON then i may just have to find the right wire that gives the 4v reading and see if it adjusts when i try moving the afm... I'll be checking all this tomorrow though as i was having an MX5 day today, Hopefully someone with a safc might stop by and know the answer to my troubles

HAILERS2

Next time you look at the SAFC screen and observe the 1.5v...........just go up front and remove the plug off the afm. The voltage (shown on the SAFC) should go away if your connected to the right wire.

Kamatari

Right so looking at voltage, with the air flow signal wire is disconnected the original voltage when set to on is 1.5v and when the car is started says 7.5v and increases when throttle is applied.

When the air flow wire is connect it reads 1.5v when on but then the car won't start, if it does manage to it only says 2.5v. When I take the air filter off and manipulate the voltage increases....

From what you've said I was expecting the voltage to decrease...

I did find another wire that is effected with the air flow meter which I've also tried splicing into, this wire has a voltage of 5v when on and the car will start but then revs drop and cut out but the voltage doesn't change, when I'm not spliced into it the voltage reads 7v and increases when the flap is manipuated...... Argh

Kamatari

just to add on as i was writing on my phone at the time,

The original wire that i was connecting to and this second wire i found both give a voltage reading and when i unplug the air sensor the voltages drop to 0.

Ive checked all the other pins and theyre all either 12v feeds or not really any voltage. Going by the FSM saying that the voltage should be 4v and then drop to 2-3v when idling, its seeming as the orignal wiring doesn't do that BUT my car does idle a bit high so i would expect to see a bit higher voltage but i dont get what is happening as there is a big voltage difference between the orginal air flow signal wire and when the afc is plugged in as the AFC only reads 2.5v if the car manages to stay started which is fine as it also brings the idle down... but as soon as the throttle is touched the car cuts out.

What ive also tried is just connecting the input wire (white wire) to the original wiring just to read the voltages but even with just the one wire attached the car wont start! ive taken off all my wiring, redone the ends and tried again but still no joy.

I was hoping with this second wire i found i was getting closer, without anything attached it gives the same reading as the first wire and when the car is started it also reads around 7+v although manipulating the flap has no affect.

really dont get whats wrong and apart from this thread no idea where to go for help

HAILERS2

The very most a afm can output is 5vdc.

The voltage should decrease and not increase as the cone in the afm is moved aft.

I'm not wrong about what I just said above.

The afms plug should have five wires. Two are ground wires..........one is a ref voltage wire with 5vdc coming from the ECU..............one is green and is the output wire From the afm to the ECU............and the last one is a green/orange wire that is a air temp dedicated wire.

None of these wires should ever read over 5 vdc when the connectors are on the afm and ECU. You check the voltages by backprobing the wire in the plug with the plug on the ECU.

What is the color of the wire you think is the afm wire that you have cut intwo and spliced into the SAFCs white/yellow wires? If it were a USA version that wire should be colored Green.

A correction: in a earlier post I might have called this green wire as being green/black. If I did........sorry 'bout that. Should be pure green.

I need to reread you last two posts but I've got something to do right NOW! or else.

Kamatari

I could be moving the wrong part to be honest, i took the air filter out and moved the flap thats undernearth.

But as for what the air flow signal wire is reading it is saying 7v which increases with revs... The wire that i've spliced into is in the middle plug and is in the same location as the apexi guide, this a green/blue wire which i believe is right, The other wire that i found is a light green and yellow wire. These two wires seem to be the only ones giving a voltage other than 12v when the car is set to ON and when the plug from the AFM is removed the voltage drops to 0

I cant remember if there is a pure green wire but i will check

If we manage to work this out then ill have a good write up and put together a diagram for UK owners heh:p

HAILERS2

Seeing as how it's not a USA car/wiring then maybe my colors are not right for You.

I'd remove the elect plug from the afm. Write down the wire colors and maybe write the colors on this site.

Even better contact HIGGI and ask him to download the page out of the wiring diagrams that shows the afm and the wires going to and from it. THAT should confirm what the wire color is at the ECU for the input from the afm. Yep. That's what I think you should do for sure.

Just in case: When reading wires at the ECU, the wiring manual shows the plug from the WIRE side of the plug. The wire sockets are read from right to left in a up/down method. Like 3a would be on the top row far right. 3B would be directly under it....3C would be on the top row and second from last on the far right and on and on and on til the left end of the plug arrives.

Kamatari

Could be, i'll give it a check anyway as you never know! i'll also check the plug and give hIGGI a message now

Kamatari

If my AFM just so happens to be reading 7v and its all the right wires, i take it ive got something wrong with it?

Also i am moving the right part to see the voltage drop? the flap that is under the air filter when its removed?

HAILERS2

Series four cars had a afm that had a vane or if you will a hinged flap. Series FIVE cars had a afm but it has a cone shaped center that moves aft if you push against it.

You have to remove the air filter to access the area of the afm that has the vane or cone.

I was sure your car was a series five car that had a cone center in the afm. Yours is series five isn't it?

IF you see 7vdc and the meter is good AND the plugs are connected to the afm and ECU (you'd be backprobing the given wire at the back of the plug) then it wouldn't be the afm that was the problem but ECU related. OR could be the meter your using that is the problem.

PUll the plug off the afm. IF you can see the wire colors (might not be able to see 'em because of the way the plug is insulated) you should see approx 5vdc on the brown/white wire in that plug. What do YOU have on that brown/white wire in the afm plug (plug disconnected and key to ON only).

Opps, no problem with the ECU or afm because the car runs ok with the SAFC removed from the circuit.

bumpstart

i have a horrible suspicion that the N322 is using the 12v AFM system from the 12at ,, both use a dizzy and fuel only ECU
and thus needs the sort of SAFC that is for 12v AFM's


i also suspect there may be some error in the air temp sender circuit and this may amount to changes in the mass flow calculations despite output voltages from the flap being similar

Kamatari

I believe mine is more a series 4 than it is 5...

if we went the AFM being 12v instead of 5v i would need to try and find an AFC that works with 12v? Although should i not see my AFM voltage set to 12v and then decrease?

Also does anyone know an AFC that works with a 12v AFM?

Kamatari

Ok ok, so just trying to read through things at the moment, S4's are meant to have an afm which is 0-5v and the voltage decreases as the vane is moved.

Now from what ive been coming across is that the first gen rx7's had a 12v afm where the voltage increases as the flap is moved and idle voltage should be around 5.5v so it is looking like this is just another thing that the UK got done over with.... not only did we not get a proper S5 apart from the rear lights...we didnt even get an S4 afm...

So now if this is all true my apexi neo will never work with my car and ive got the problem of trying to find and AFC that will accept a 12v AFM (or buy another car)

HAILERS2

Another reason I shouldn't be writing on this thread. Writing about something I don't anything about. Sorry 'bout that. Gone.

HAILERS2

Nope. I didn't know anything about that 12v deal.

I've read the manual NZCONVERTIBLE gave us called the Training Manual and it showed different versions but I didn't notice anything like that. Learn something new every day.

That training manual can be found here: http://foxed.ca/foxed/index.php?page...nual#secondgen and it's found waaaaay down towards the bottom of that site on the far left hand side. Has to be downloaded though.

EDIT: I went back and looked at that training manual and sure enought your uses a 12v signal instead of the 5vdc for USA/AUSTRALIA cars. See attached jpg.

Yeah. I'd start wondering if the SAFC is useable on your car. I'd go to the SAFC factory site and ask them. I believe they have a place where you can write them questions if memory serves.

And I'd swear to the gods that the voltage on a USA version decreases as the vane/measuring plate moves to the more fully open positon. Geez, I'm going to have to go out and look at my car(s) to make sure. You've instilled doubt in my mind about that. But I'd bet a hundred bucks the voltage on a USA decreases as the vane goes more open and double down on that if challanged. Don't care what the words on that training manual say about that.

Heck the USA FSM shows the voltage at approx 4 vdc when key is ON engine OFF and 2.5 or so volts at idle so I know I'm right about USA versions. NOT other versions that use 12v though.

bumpstart

note the 12v version shows an inline resister
and while it would be hazardous to think this works anything like a regulated 5V Vref supply
\it does however pose an interesting place from which to "play" the afm signal rich and lean

so while for the OP i dont think this SAFC will work for you ,,
a little bit of for thought and further investigation into that resister in/near the 12v AFM
may offer an alternative method in which to offset adjust the mixture

hIGGI

iTrader: (7)

Here you go with requested manual page :

http://rx7cz.net/pics/IMG_0663.JPG

Kamatari

Thanks for all the replies! I will look into it a bit further....

At the same time now im starting to consider going down the megasquirt route for a new project so just trying to find ut all i can about that

HAILERS2

Thanks. Looking back that's what we needed in the first place. It shows the 12v coming from the Main Relay instead of the 5v (USA version) and it also has an additional wire Lg/Y coming off the AFM going to the ECU, that I've no idea what it does in life.

Plus your ATP also has 12v going to it instead of the USA version that has 5vdc. And I notice there is 12v going to a AAV or anti afterburn valve and the USA version does not have that solenoid. USA has a anti afterburn valve as part of the ACV but it's not electricaly controlled.

The ATP and AAV wouldn't have effected the SAFC at all but it's just something that caught my eye as being different than USA versions.

Hope you can sell that SAFC and not lose much money if any. Thanks to HIGGI for helping out. Bye.

meerkat8701

just wanted to say thanks to HIGGY for putting up the wiring diagrams. very helpful!