Nistune Forums

this is quite strange.

Test in my bench with DLP
- Input 1+2 = AFR 0-5 volt (brown wire from LC-1, GND to DLP GND)
- Input 3+4 = Boost sensor (grounded to DLP GND)
- Input 5-8 connected to GND on DLP

As you can see from the pic the LC-1 output is quite shaky, however the boost sensor (gradually increasing pressure on bench) is stable

This is basically the same as your issue. You can see the DLP is quite stable with boost sensor which means the DLP and grounding is fine

Also it shows that there are issues with the wideband to DLP part of the interface. So its not a software issue

My lookup tables:

AFR1.CSV
Innovate_AFR
0000,7.35
5000,22.39

AUX1.CSV
AFR_Volts
0000,0
1000,1
1500,1.5
2000,2
2500,2.5
3000,3
3500,3.5
4000,4
4500,4.5
5000,5

AUX2.CSV
Boost_Volts
0000,0
1000,1
1500,1.5
2000,2
2500,2.5
3000,3
3500,3.5
4000,4
4500,4.5
5000,5

AUX3.CSV
Boost_PSI
0000,0
5000,36.259

Further testing

My LC-1 is proving very unstable on the bench tonight it seems. Even the regular serial output is moving all over the place. Might try another recalibration

What it is showing is the same problems - here this screen shot LHS = DLP and RHS = MTS reported

Even doing this with the Logworks application and LC-1 without Nistune

What I have noticed is using a terminal program and monitoring the DLP voltage (text output) vs mulitmeter is about 0.05 volt discrepancy. This is enough to cause minor AFR deviations and would need to be compensated in the look up table file

Going back to the vehicle and trying out on the other O2 sensor tomorrow and see how that goes. DLP inputs are stable but minor voltage discrepancy and I dare say your wideband output is to blame for its fluctuations. What does the serial output look like on this?

looking at this now. on the bench I'm getting wobly voltage but Innovate and multimeter report fine

Log shows voltage (DLP reported), AFR (DLP reported) both are shaky and AFR (Innovate) which is smooth

Problem is to do with DLP picking up on voltage noise/fluctuations

I've attached a photo of what these look like from a PC power supply

Here is a sample of data of the DLP using tera term

2.80V
2.92V
2.74V
2.72V
2.66V
2.62V
2.72V
2.84V
2.82V
2.75V
2.94V
2.91V
2.81V
2.60V
2.79V
2.72V
2.92V
2.81V
2.87V
2.90V
2.83V
2.81V
2.88V
2.84V
2.66V
2.69V
2.85V
3.02V
2.84V
2.78V
2.97V
2.82V
2.75V

Basically what I am trying to point out here is that the data being fed from the DLP A/D converter is picking up a lot of noise, where this is filtered on the wideband output

The multimeters I'm using here dont flutuate with that noise but the scope picture and the raw data from the DLP do

To perfrom a test of your data coming from the A/D converter use the following:
Channel 1 (AFR) press 'Z' to get a reading in volts (like the above)
Channel 2 (AUX1) press 'X'
Channel 3 (AUX2) press 'C'

Pressing these keys when connected to the COM port will report the voltage

Similar test of just the boost sensor (no input power involved here) connected to Channel 3 whilst holding C button

0.37V
0.37V
0.36V
0.36V
0.37V
0.37V
0.36V
0.36V
0.36V
0.34V
0.33V
0.33V
0.34V
0.33V
0.32V
0.30V
0.32V
0.34V
0.32V
0.32V
0.32V
0.27V
0.22V
0.21V
0.19V

Even on the scope this is quite smooth

What I'm basically trying to point out here is that Nistune is taking the data fed from the A/D converter and using it against a lookup table and printing it out

The boost voltage which is just using USB only voltage shows on the meter matching exactly what Nistune shows

If the AFR is out on the UEGO then hook up Pins 1 and 2 together to show the AFR raw voltage inside Nistune. Compare this against your meter. If the voltage matches but your UEGO display doesnt match the AFR shown then there is a problem with the lookup table being used

With the noise, I'm not sure what you can do here since its a problem with the DLP A/D converter picking it up from the car (like with my bench power supply). Better filtering (capacitors perhaps) may be required to stabliise the signal. Will check with PL on that one

Answers to questions:
1. Should the AFR readout be so jumpy?
NO - output from the UEGO is likely very noisy and DLP has a high data rate and showing all the noise as fluctuating voltage
You have noticed your boost out line is smooth in comparison (like mine)

2. Will the serial output be just as jumpy? (dont want to use serial)
It should be fine. It is smooth with the LC-1 output but the 5V line is shaky. Would suggest using the serial output if you cannot get the UEGO output voltage smooth.

3. What do you suggest to get AFR in line with gauge and stable readout
Need to check. Some type of filtering on the AFR line to smooth it out is required

4. What and why do the AUX give me a reading? Nothing is connected to the other dlp channels
Nothing connected to DLP channels means the input is 'floating' this causes random numbers to display in Nistune. To calm this down connect ALL unused DLP inputs to the GND wire using single strand wire

Everything you said seems to check out on mine, it's the AEM Uego causing the noise.
I have been using serial reliably with the AEM but still want to fix analogue to cut down on the amount of cables I have hardwired under the gear gaiter.

I accidently realized this when I switch my gauges off, the dlp readout through Nistune went stable. I have all the gauges hooked onto what was the front fog light switch.
My knock sensors (ks4) analog out is a good guide as it reads 0.15v idle, it jumps around franticly along with all the other dlp readings.
As soon as I unplug the AEM power connector at the gauge all the DLP readings become perfectly stable.

Just need to fiqure out how to stop the AEM making noise, then offset the lookup tables to match the gauge display and it Should work.
I will try and move the earth, not sure how else to stop the noise. Another member on here did report the AEM cause interference problems also.

Also check other electrical noise (as mentioned in the Installation and Diagnostics manual)

I found tonight using the LC-1 output and voltage derived output via the DLP that both held nice steady same value AFRs throughout the test run on my R31

This was compared to the same setup but on the bench with a noisy voltage output from the PC power supply I was using. So car had lower noise levels than my bench for that exercise!

This is all fine and dandy (and I must admit I am thouroghly confused lol) but how do you explain the fact that two seasons ago I was using this exact same setup and I did not have this issue? The only thing I changed was my laptop and hence new software.

I didnt get much of a chance to tune it last season (except on the dyno where I used a sniffer) and I just got my car started yesterday. I w+ill try to play around and report back. Looks like I will most likely have to switch to serial. Another cable added to the ol' rats nest under the passenger side lol.

I cant explain it unless the laptop USB input is experiencing more noise than the last laptop. Software versions are not an issue.

Since these tests I've been running DLP and the same LC-1 in these logs on my R31 and both put out nice smooth signals compared to my bench (which had a noisy power supply) so clean voltage is the main thing to keep in mind

See attached log and compare LHS and RHS (using Innovate configuration and DLP as second config). These are nice smooth logs which match each other and the boost curve is steady. Using 0.10.16 with that one