sherwinZ28

I've been trying to wrap my head around finally tuning my car. I changed out clutch (Spec Stage 1), header gaskets(Percy's rebuildable), spark plugs and wires. I drove it around and it was still running very rich, can smell heavy fumes from exhaust. Replaced with stock programming and it seems to run better at idle, less gas smell. I then put in a tune that closely resembles hot cam(found on internet). Logging with Torque on Android for now since for some reason my obd-2.com software doesn't work with my laptop. Here is a log in csv format, let me know if you need more detail. It is throwing P0303(Cylinder 3 Misfire) and P0441(Evap Emission).

Thanks,
Sherwin

Mega File Upload - trackLog-2015-Jul-24_21-56-52.csv

Injuneer

Guess I'm not smart enough to figure out how to download from that site. Clicked on "Slow Download" and nothing happened.

sherwinZ28

How strange, I can't download it either, is there a better file hosting, perhaps I can email it.

Thanks,
Sherwin

Injuneer

Impossible to translate that to something useable.

sherwinZ28

Ok let's try this:

https://www.dropbox.com/s/xgujjhm8kn...56-52.csv?dl=0

Injuneer

Worked.

I'll take a look at it. Preliminary peek indicates a scan rate of 1 frame per second, which isn't going to display the complete data from the PCM, which is updating almost 10 times per second. Limited number of sensors and PCM parameters, but I'll see if anything is obvious.

sherwinZ28

I've got an updated log in which I changed the left/right FAST O2 tables to match as well as the Individual Cylinder Fuel Trim (at idle) values in JET. I also changed the scan rate as well to something a bit faster. I've been doing some reading and it seems I may need to change the MAF tables as well since I have a different CAM. On startup the car is very rich(?), I can smell heavy fumes from the car. Not sure what troubleshooting I can do besides posting the log.

https://www.dropbox.com/s/hqox7yso22...12-58.csv?dl=0

Injuneer

The increased scan rate simply causes it to duplicate the same item data value about 22 lines in a row (2.2 seconds). Now we only have data every 2.2 seconds.

What scan program is this? It's about the worst I have ever seen. It's missing a ton of key data including:

-MPH
-TPS V
-TPS %
-Fuel Correction CELL
-Knock Count
-Target idle RPM
-IAC position
-EGR duty cycle
-EVAP duty cycle
-Barometric pressure
-Ignition volts
-Injector base pulse widths
-Injector duty cycle
-DTC's

At 20:34.2 you appear to go WOT, and the PCM shifts to PE mode, setting a target A/F ratio of 12.7:1. The L O2 sensor seems to drift from 875mV down to 695mV, R O2 from 910mV down to 760mV. If those are correct, it looks like it 's running short on fuel. But, only having one data point every 2.2 seconds makes any real analysis impossible.

In what may be the idle cell (and there is no reference to tell me what cell it's in) the LTFT's are adding 25% extra fuel (the usual upper limit) on both banks. The STFT on Bank 2 is adding another 7% fuel. In most other cells, it's adding fuel on both side, and not uniformly..... at 2090 RPM in one sequence it's adding 2.34% on Bank 1 and 20.3% on Bank 2.

Not sure what more I can say.... the data is really not useful.

sherwinZ28

Wow, so Torque app for android is not useful then. For some reason my old obd-2.com software does not work and neither does scantool.net software on my new laptop (Windows 7 x64). I'll forego using Torque and try to find something better and get back to this thread...I appreciate the effort and help. The fact that you can pinpoint fuel issues based on the mV of the O2 is interesting. Now I know what data points you need.

Thanks again!

GaryDoug

Here's a torque log file with all the standard OBD2 values you will get. To get any more, like target idle speed, IAC position, TPS-V, misfire counts, knock sensor counts, etc , you will have to install the free add-on app TorqueScan. That will add a lot of enhanced GM PID's.

I left in the default acceleration columns.
http://www.mediafire.com/view/qfhu4s...1_23-58-24.csv

To make the scan quicker, have nothing displayed on the screen (blank dashboard page). That way it won't have to update any gauges while running.

Injuneer

Thanks Gary!

GaryDoug

Please be aware that if you use my OBD2 app, GDscan2a, it will not log standard parameters (1st page) in the same file as the enhanced ones (last page). Nor can you run both scans at the same time.