Jaycar DFA, and 02 Sensor wiring issues *Sigh*

[RG.net]

Hi guys,

My car is finally out of the shop, however we are having a few little problems.

First of all, i have a jaycar DFA which i planned to install to the NB, however it seems that it doesn't want to respond and stays on load point 128 when the engine is running. With the car on "reds" it responds like it should, toggling through load points.

Now we have checked with the mutli meter, and we are 100% sure that the AFM signal is the pale green and black stripe, but it's just not cutting it.

This DFA was working on my other car, just one day before i put it into the MX-5, so it wouldn't be faulty.

Are the NB8A's not compatible with the DFA, or is there something i am missing? i know there are (were) a few forum members running a DFA, but i am unsure if anyone has done it with an NB.

Secondly, could someone get me a picture of their 02 sensor plug (that sits infront of the cam cover) with the wire colours exposed? we forgot to mark them upon removal

Thanks in advance fellas!

Adam.

PS. this is what the engine bay looks like (minus the bolt in the Vac line )

[Fatty]

the dfa has a relay on the +12v input, which has a pot that you can fiddle with to alter the voltage at which it switches on. me thinks you fiddled with this pot to get it to switch on in your micra (?) , but the mx5 running voltage is slightly different. just adjust the pot downwards so that the switch on voltage is a bit lower. the relay is actually not really needed, i guess it's a bit of a safety device... but in my car i just left it out and hardwired it instead.

[RG.net]

the dfa has a relay on the +12v input, which has a pot that you can fiddle with to alter the voltage at which it switches on. me thinks you fiddled with this pot to get it to switch on in your micra (?) , but the mx5 running voltage is slightly different. just adjust the pot downwards so that the switch on voltage is a bit lower. the relay is actually not really needed, i guess it's a bit of a safety device... but in my car i just left it out and hardwired it instead.

To be honest, i bought the DFA and pretty much tossed it onto the micra, it all worked well.

I'll have a look at the input tomorrow, hopefully that fixes the problem i am having, it could'nt really be anything else could it?

Thanks Fatty.

[Alex]

Secondly, could someone get me a picture of their 02 sensor plug (that sits infront of the cam cover) with the wire colours exposed? we forgot to mark them upon removal

Thanks in advance fellas!

Adam.

Again

viewtopic.php?p=357299#p357299

[RG.net]

Secondly, could someone get me a picture of their 02 sensor plug (that sits infront of the cam cover) with the wire colours exposed? we forgot to mark them upon removal

Thanks in advance fellas!

Adam.

Again

viewtopic.php?p=357299#p357299

3 years on, i need the other size this time, can barely make it out in that picture

Edit, scrolled down a little, and there it is! thanks again Alex

i'll put them in here for an easier reference when i am on the iPhone.

[RG.net]

Ok Fatty, i've taken the cover off the DFA, and the only "pot" i can find is the blue one with "1K" listed under it. I've marked the one i am talking about.

Is this what i need to adjust, or is there something else i am not seeing?

I didn't build this DFA, i got it dirt cheap and thought i would give it a go on the previous car i had.

[Fatty]

nope not that one.

hang on a sec and i'll see if i can find my instructions. did you not get the instructions with yours?

[RG.net]

Reading them now, it says the following

"Trimpot VR4 sets the voltage at which the DFA switches in its interception, Turning the VR4 clock wise sets this voltage to a lower level."

the trimpot VR4 appears to be next to the LED light on the left.

I guess i'll give that a shot later today and see how it goes.

[Fatty]

yeah thats it. if the led is on while the car is running, then the dfa is switched on. if the led is off, then the dfa is off. so just adjust that pot until the led comes on.

if the led is already on, then your problem lies elsewhere.

[RG.net]

yeah thats it. if the led is on while the car is running, then the dfa is switched on. if the led is off, then the dfa is off. so just adjust that pot until the led comes on.

if the led is already on, then your problem lies elsewhere.

When i put the key in and turn it once, the DFA comes to life, and acts as normal, but on "reds" it will still go to load point 128. i tryed adjusting that pot, but it did nothing.

I read somewhere that it takes the battery voltage, now my car is currently using a booster pack as the battery is dead, could this have something to do with it?

The power and ground isn't wired to the ECU either, unlike it was in the micra

[Fatty]

what do you mean by on "reds"... the engine is running?

is the LED on ?

load point 128 is either 0v or 5v, i think it's 5v as it's at the top end of the scale. are you sure you've tapped the correct wire... you haven't tapped into the power supply for the airflow metre have you, instead of the output?? easy to check, get your multimetre and rev the car and you should see the voltage on that wire change rapidly. if the voltage stays constant, you've got the wrong wire.

power and ground not being wired from the ecu should not be a problem. i found that the power from the ecu could not supply enough current so i tapped power straight from the ignition, which i think you have done as well so it should be fine.

having a dead battery should not matter, as long as the car is running the alternator will be supplying enough juice... err, i think.

[RG.net]

what do you mean by on "reds"... the engine is running?

is the LED on ?

load point 128 is either 0v or 5v, i think it's 5v as it's at the top end of the scale. are you sure you've tapped the correct wire... you haven't tapped into the power supply for the airflow metre have you, instead of the output?? easy to check, get your multimetre and rev the car and you should see the voltage on that wire change rapidly. if the voltage stays constant, you've got the wrong wire.

power and ground not being wired from the ecu should not be a problem. i found that the power from the ecu could not supply enough current so i tapped power straight from the ignition, which i think you have done as well so it should be fine.

having a dead battery should not matter, as long as the car is running the alternator will be supplying enough juice... err, i think.

"reds", car is ready to crank the engine over. Pretty sure we have the right wire, we have checked it several times, i'll need to borrow his multimeter as the car is now at home.

I have also tapped from the ignition.

[Fatty]

i'm not sure why you think the dfa is not working properly

if you haven't started the car, then how do you know if the dfa will cycle thru load points??

[RG.net]

i'm not sure why you think the dfa is not working properly

if you haven't started the car, then how do you know if the dfa will cycle thru load points??

I have started the car with the DFA plugged, and it doesn't respond. I haven't checked it since tinkering with the pot, but now on "reds" it doesn't respond when it did before hand.

I'll see how it goes when the booster pack has enough power to kick the car over.

[RG.net]

Ok, the car has been started, and the DFA is doing the same thing, and it hasn't responded to me adjusting the "pot".

Has anyone actually installed this or an SAFC into an NB before? maybe i do have the wrong wire after all

When i attempt to accelerate, the car wants to die ... mmm.