elior77

Hey !

I got my Spartan Lambda Sensor
14Point7

How do I connect it to my DIYPNP ?

I noticed the the CLT and the IAT are not the same when I switch the key to on (no engine start)

I get about 10C delta between them, as I understand they should be the same when the engine is cold and off...

Any way to fix this ?

Thanks !

Braineack

iTrader: (62)

did you run the thermistor calibrations on them?

did you build your DIYPNP?

elior77

Yes and yes, both on same calibration

Joe Perez

iTrader: (8)

The red wire (+12) can be spliced to any convenient source of 12v, such as the white/red wire at the ECU harness.

The black wire (electronics ground) must be spliced into one of the ground lines at the ECU, which are generally also black.

The white wire (heater ground) can be connected to ground anywhere, including the same place as the black wire.

The green wire (wideband output) must be connected to the DIYPnP's O2 sensor input, and you must cut the signal wire from the stock O2 sensor rather than just splicing into it. The location of this line varies by model year, which you have not told us.

The software must then be reconfigured to recognize the wideband signal.





They should be within a few degrees of one another. Despite what some people thing, an overnight park is long enough to equalize the temps.

Which one is closest to the actual ambient temp?

elior77

My ride is a 97 miata, I think both are equally far from ambient, CLT higher and
IAT is lower, I can get precise numbers if needed.

Thank you for your answer :>

Braineack

iTrader: (62)

did you use RX7 CLT and GM (or RX7 AFM)?

elior77

I calibrated them as the diypnp for miata 97 say

tuckntruck

iTrader: (1)

Did you calibrate the numbers for the MAF accidentaly? they give both

elior77

I did:

tuckntruck

iTrader: (1)

If you are using the gm open element IAT probe, those are the wrong values. If you left you MAF in place those should be correct ( can't see the model year version of the diypnp instructions). If you are using the gm IAT , the resistance values are further down

Braineack

iTrader: (62)

just use GM in the drop down.

elior77

The GM settings are:
bias 2490
-40C = 100700
30C = 2238
99C = 177

The settings I found on DIYautotune for GM open element IAT are:
bias = ?
Temperature Ohms
48 degrees F 7000
87 degrees F 1930
146 degrees F 560

http://www.diyautotune.com/catalog/g...tor-p-116.html

what should I use ?

Now I got the CLT and IAT at the same temp (cold engine) with:
bias = 1800
-20C = 16150
40C = 1150
80C = 330

tuckntruck

iTrader: (1)

Use the GM DIYautotune supplied numbers.

Your iat and clt will never really be the same, unles the car sits for a good while in an area with 0 temp change.

Give you iat temps a gut check while driving. Realistically though, consistency is more important than exactly correct numbers. As you tune your maps, as long as the sensor returns the same value for the same temp repeatedly, your tune will work. The gm IAT and CLT sensors are the same, one is closed element, so it Is slower to react. ( notice the values are the same for both GM elements?

Are you running boost? If yes which type(turbo or blower)? 10psi on a 60 deg day (without IC) should be above 160* iat, which should run back down slowly at idle.

elior77

I run turbo @ 8psi now and upto 12psi when my boost controller will land.
I have an IC.

I drive the car only at weekends so it does sits cold for days.

What bias should I use for GM numbers ?

So I should use this numbers ?
Temperature Ohms
48 degrees F 7000
87 degrees F 1930
146 degrees F 560

I understand what you say about consistency.

My CLT is the original sensor (miata 97) and the IAT is the open element GM sensor.

Thank you

tuckntruck

iTrader: (1)

The much higher latent heat content and density of the coolant mean that it will be much slower to react to temperature changes in a day. If you take a reading at 11am, the IAT air will be slightly below ambient, while the CLT will nearly be the same as the 6 am temperature ( coldest hour of the day normally)... That alone can vary the temps 10-20 deg... So I wouldn't worry too much about them matching...

Start the car, let it idle for 20 seconds, then check the temp... It should be almost ambient( as long as the sensor us pre throttle body)

JasonC SBB

Bah, black wire signal ground should go to the sensor ground pin on the ECU.
The heater ground should go to the cylinder head or engine block.

I don't just play analog electronics engineer on TV, I've been doing it in real life for 20+ years.

elior77

Can I just cut my OEM O2 sensor from its plug and connect my wideband to this plug ?

tuckntruck

iTrader: (1)

No, you would have to splice it, you will have better luck running the controller output (analog) to the ECU pin in for 02 sensor, grounding the controller at the ecu ground, or use a db15 spot to ground it to the ground pin of the adapter board if you like. Since your already over by the ecu, run the switched power line to the ecu, or lighter socket or something, just not the radio. You prob want the sensor power from something that cuts off with engine start.

elior77

Is this correct ?:

12V Red wire connect to 12V on the DIYPNP board
GND Black wire connect to GND on the DIYPNP board
GND White wire connect to GND on the DIYPNP board
O2 Green wire connect to O2 on the DIYPNP board
NB Brown no need to connect
OK ?



They say I must use a 12v that is live only when engine is running...

Thanks !

tuckntruck

iTrader: (1)

No, pull the power from something other than the ECM.

ECM is live power whenever the ignition is on, or start. It does not cut out, or the car won't start. Not to mention, I don't know that the pc board can handle pulling that much power through it. The only wires fed directly to the megasquirt should be the ground and analog output. The heater ground should go to the engine block, and not share a ground with the ECM, or you could have noise issues.