DIYPNP Idle Issues
 

I know idle tuning has been covered MANY times, but I am having a couple issues that are getting quite frustrating, and per the various threads, should have been easily fixed. The issue is regarding my AC compressor in closed loop idle (This is a DIYPNP on 3.3.1 installed in a 2000) . First off, when trying to tune the PID fields, it is not reacting as it should be. In the idle test mode, I found my min and max steps, and everything went well. After putting in the values, I found that very little changes when playing with the I value. When the PID values are all at 0 the car idles at roughly 1000 rpm (850 is my target), and once I input "10" for the I field, the idle drops to 900. From there I can enter values up to the max 200, and the idle stays at 900. When changing the P value, nothing really seems to happen, and nor does when entering in the D value. I am able to get a good idle (even though the numbers appear not to change anything); however, once the AC comes on it goes downhill. The RPM's fluctuate from 300RPM up to 1200, and keep going until the compressor turns off. Nothing I can change seems to reduce the initial dip and oscillation. Under "AC idle up" control, I can put in any values for the duty/rpm adder with no effect; however, when changing to "high" polarity, my RPM's when the AC is off do in fact increase about 500 (still changing duty/rpm change nothing). I am confused at this point and nothing is really making sense.

FWIW, I don't think it is related, but my CLT and IAT sensors are reading off, and I cannot control my radiator fan. My CLT reads around 130 when the car is at ~200, and IAT was reading 70 yesterday when it was 20 out (On initial warm up, before any possible heat soak). I programmed them in the correct units and bias per the diyautotune website. I can also verify with the stock ECU, the CLT readings are accurate. For the radiator fan, I wired it and verified with a multimeter there were no cold solders, and no matter the entered values, the fan is ALWAYS on.

Thoughts/Ideas? I tried contacting DIYautotune 3 times, but haven't gotten any replies back :/. Part of the reason I purchased from them was because I heard their after sales support was fantastic. Maybe it's just a bad time of year for them? MSQ and screenshots uploaded!

Recalibrate the sensors using the 3 point curve generator with matching bias resistance in Tunerstudio. In my experience DIY's calibration numbers were inaccurate for the GM open element IAT sensor.

CLT and MAT should agree within a few degrees of the ambient temperature when the engine is "cold" (steady state thermal equilibrium with ambient).

I assume you mean this option? Since the resistance/value is not linear, how would one go about re-calibrating this table?

Choose your sensors from the Common Sensor drop down list. Make sure the bias resistance is correct and click write to controller.

TS makes the new table for you by calculating the coefficients for the Steinhart-Hart equation from those 3 points.

If you are interested in viewing the most recently burned table then look in the TS project folder for std_ms2gentherm.log and open it in notepad++.

I think I must be misunderstanding something. When selecting "mazda" (it's the stock sensor), it populates similar values. My car is at operating temp (as per my oil temp gauge), but the CLT is still reading ~130. If I take that and enter in the 2490 resistor bias, I get 300+ degrees. Am i missing something?

Use the RX-7 sensor for CLT.

With RX-7 CLT selected, I am now reading 10 degrees lower than before. So 120 when it should be at 200.

If you sure the coolant temperature is 200 F and the bias resistance is correct then you could try removing the sensor and bench testing it in water. Record 3 data points and enter the values in the curve generator.

So after getting my 3 values, I found the oddest phenomena (I don't live in Colorado, this is actually happening). When I go into TS and change the CLT values to get accurate readings, my AFR's, battery voltage gauge, and clt/IAT readings start bouncing all over the place similar to a poor ground. The signals all become very jittery. As soon as I re-calibrate the CLT to the normal spec, everything acts as normal. What's going on here? Why can't I just change my thermoresistors so that they read normally?

What were the data points?

I can't seem to find my notepad at the moment, but I'm pretty sure I had
F | Ohms
----------------------
32 | 12000
--------------
70 | 6300
--------------
200 | 400

and I just used the 2490 resistor bias as diyautotune listed as I don't have all the required info to calculate this (and I assume it should be similar?) Weber Bias Calculator

Why would this change my AFR's etc? Shouldn't these readings be on a separate circuit altogether?

it didnt.

Let me datalog for you guys, this doesn't make any sense to me either. Give me a sec.

I tried the measured values on ms3 with jimstim and there are no problems albeit clt went up 13 F.

You may have some hardware problems.

So here are 3 data logs.
1. On the RX7-CLT settings
2. On the benchtest settings (Really squirrly huh?)
3. After RX7-CLT settings

Since you guys say that the circuits are not tied together (which does make the most sense), the other thing I can think of is that since this took my temp readings from 130F to a more proper 170F+, is there something that would switch when the car reached operating temp? It just doesn't make sense.

Try setting fixed field min and max in MLV so the signals do not look so "squirrely".

http://imagizer.imageshack.us/v2/640...0/713/6zhz.png

After spending more time toying around with different numbers, I found that there is no issue changing the numbers, the issue happens only once the coolant >~160/170. I can change the values in the table to whatever I want, and as long as my coolant reads under this number, everything works fine. As soon as the car gets above this, the ECU occasionally disconnects from the laptop, my voltage/afr readings go crazy, etc. Is there some setting that's only engaged once the car is warmed up? This obviously isn't a calibration issue, this issue lives somewhere else.

Your ego correction activates when CLT >= 160 F. Try setting ego authority to zero.

You have the stock narrowband o2 sensor which could be the problem.

I suggest leaving ego off until you have a wideband, and in the meantime do not tune with the narrowband.

I didn't see that the EGO was enables and set to a narrowband. I have the MTX-L (Would never have even tried to tune without a WB02.) I will disable EGO, then see if this solves the issue!