PLX SM-AFR question..............

[FreddyG]

Hi Guys!

While logging with my PLX SM_AFR WB02, instead of it giving me the varying voltage readings (0-5v=10-20AFR), it's giving me a flat 3.5v. Has this happened to any of you before and if so, could you Please tell me how you fixed it?

I have the SM-AFR+DB5 (gauge) combo and the gauge still registers the AFR. It doesn't stay at one certain reading, it works as it should.

Thanks in advance! :cheers:

[Chalky]

Have you selected the proper pids when you setup the M250?

Without the proper pids, you will not get any reasonable readings.

[FreddyG]

Hi Chalky!

Thanks for the help! :cheers:

I think that I've got the right ones selected, but am open to any and all suggestions, criticism, or advice that you'd be willing to share.

Here's my current selection of PID's:

http://home.comcast.net/~onebadassc5/PID_Selection.JPG

[Chalky]

Looks good. DId your get the pic I sent showing the wiring diagram?

Pics courtesy of Bruce Melton!

[FreddyG]

I didn't get the pics, but I looked at the attachment and I didn't put the capacitor on there. Could that be part ofthe reason for the lack of slope or the flat readings?

Thanks for the help Chalky and Bruce Melton too! :cheers:

[Chalky]

I didn't get the pics, but I looked at the attachment and I didn't put the capacitor on there. Could that be part ofthe reason for the lack of slope or the flat readings?

Thanks for the help Chalky and Bruce Melton too! :cheers:

No. Shouldn't make a difference. I can PM the pics using IM.

Did you open my attachment I included in my previous post? That shows you the wiring diagram.

[FreddyG]

Yes Sir I did open it up and mine is wired the same way except that I didn't use the capacitor.

How can I check and compare the findings? I sent an e-mail to Nick at PLX and am awaiting an answer from them.

Thanks again Chalky! :cheers:

[Chalky]

Are you using V1 or V2?

[FreddyG]

I've got V1.

[Chalky]

http://www.plxdevices.com/products/m300/

Try this. M250 and M300 same unit.

[Chalky]

If it still doesn't work, I don't know what to tell you.

I don't trust the gauge. A friend of mine is running a gauge. When we hooked it up to EFILive, the gauge was not even close.

PLX can be really slow to respond to requests for information.

Drop a PM to Greg_E on this forum. I sold him my old M250.

[wait4me]

http://www.ls1tech.com/forums/showthread.php?t=739399

[pkincy]

How do you have the analog out on the PLX hooked up to analog input on the V1?

On my existing WB, I have Vout and ground hooked up to the A1 input on my V2.

On the PLX I am installing I see 4 analog outs. 3.3v, NB, WB, grnd. I presume that WB is the varying Vout. If so I should hook up WB and Grnd to the analog input on the EFILive Vx.

Do you have the 3.3V hooked up? I presume that is a reference voltage. Don't know whether it is out or in as the directions are crappy.

Good luck. I will keep you posted as I finish my install today.

Perry

[pkincy]

The PLX power plug is now assembled (comes unassembled) and installed to a ignition switched power source. The next step is to install the brain unit and plug in the analog out circuit.

I am using the WB as a Vout and the ground as the grnd. Seems simple but who knows.

I will keep you posted.

Perry

[pkincy]

Apparently my V2 has taken a crap but the V1 still works and I am also getting a flat Vout.

You have the proper PIDs selected. The key is that you were reading Analog V. That should vary around 3.3 Volts. Yours is 3.5V; mine is 3.1V. Besides a common problem that doesn't bode well for the PLX calibration. On my DIY wideband I had to develop my own formula for the calculated PID and it than worked as my gauge and a dynojet anal insertion O2 sensor said.

So I am going to trouble shoot off the analog V out.

The only thing I can think of (other than defective units) are that we are not using the proper analog outputs. Which did you use? I have used WB as Vout and Ground as grnd. WB goes to V+ and ground goes to V- on the Vx. Seems straightforward but the instructions are so lame that it could easily be missmarked.

Let me know if you hear anything from the PLX peeps.

Perry

[FreddyG]

If it still doesn't work, I don't know what to tell you.

I don't trust the gauge. A friend of mine is running a gauge. When we hooked it up to EFILive, the gauge was not even close.

PLX can be really slow to respond to requests for information.

Drop a PM to Greg_E on this forum. I sold him my old M250.

Thanks Chalky! I might shoot Greg_E a pm and ask him about it. :cheers:


http://www.ls1tech.com/forums/showthread.php?t=739399

Thanks alot Jesse, just what I needed to see!:D Really though, Thanks for the article! :cheers:

I don't put much stock in articles that were put out by magazines because a mag is in business to make money, and they make money by advertising and if unless it's a privately run test lab, that's impartial, I only put a little bit of what they say to be true. I guess you could say that I'm a bit skeptical.


The PLX power plug is now assembled (comes unassembled) and installed to a ignition switched power source. The next step is to install the brain unit and plug in the analog out circuit.

I am using the WB as a Vout and the ground as the grnd. Seems simple but who knows.

I will keep you posted.

Perry

Thanks Perry! :cheers: I have mine the same way, but it's just weird because when I step on the gas, it shows that my tune is going WAY lean (almost 17:1 according to the gauge) and at idle, it's 10.2:1 which is backwards to the way the car is set up. I just got an RMA # from PLX, so maybe they can shed some light on the subject. We'll see!



Apparently my V2 has taken a crap but the V1 still works and I am also getting a flat Vout.

You have the proper PIDs selected. The key is that you were reading Analog V. That should vary around 3.3 Volts. Yours is 3.5V; mine is 3.1V. Besides a common problem that doesn't bode well for the PLX calibration. On my DIY wideband I had to develop my own formula for the calculated PID and it than worked as my gauge and a dynojet anal insertion O2 sensor said.

So I am going to trouble shoot off the analog V out.

The only thing I can think of (other than defective units) are that we are not using the proper analog outputs. Which did you use? I have used WB as Vout and Ground as grnd. WB goes to V+ and ground goes to V- on the Vx. Seems straightforward but the instructions are so lame that it could easily be missmarked.

Let me know if you hear anything from the PLX peeps.

Perry

I sure will keep you informed!

I've got mine setup the same way, in that the lower left is the ground and the lower right is the WB. Maybe we're both wrong! I hooked mine up according to this:

PLX Users Guide.................... (http://home.comcast.net/~yourma/SM-AFRUsersGuide.pdf)

I'll tell you what they say when I hear back from them. :cheers:

[pkincy]

I was getting the exact same result as you using my old V1....a 3.1 v constant analog in V1.

However after fixing my V2 (the protocol was wrong) I plugged the analog out into the V1 analog in on my V2 and voila! perfect readings. 15.0 at idle, 14.6 at cruise and 12.8 at wot.

I would keep playing with it before it goes back. No reason to pay shipping if it is something simple.

I suppose I would put a DVM on the power switch (I did that had was 12.0 with the ignition on and no motor running). I would recheck both analog out connections, than I would reinsert and retighten the analog in screws on the EFILive fitting.

And do check the V in you are using. You need to read the V2 when it is upside down. I may have had mine in the wrong side which is for Thermocouple in not 0-5v analog in. 8 inputs is good except when you use the wrong one like I did.

Perry

[mr.prick]

http://www.ls1tech.com/forums/showthread.php?t=739399
:muahaha:
does the PLX need to be programmed like the LC1 analog outs do?

[Rhino79]

No, no programming at all.