Torque Lite advance timing issue or it could be my truck.

[96Z71ECSB]

I bought a mini ELM327 bluetooth device and I have been watching the timing advance on my truck.
I have been monitoring it with Torque Lite.
Problem: Torque lite shows the timing anywhere from -13 to -40 all the time. The only time it goes close to 0 degrees is when the truck decelerates for more than a minute.
I attached the ELM327 device to a 2000 Corolla and a 1997 Tahoe and it read timing advance correctly.

My truck is a 1996 GMC K1500 with a 5.7L vortec.
Build date is 10/95.
185,000 miles on original engine with 40+ psi oil pressure and a 180 degree thermostat. No abnormal noises.
I have never had the distributor out but the previous owner may have had it out because it looks like the intake gaskets have been done.
No OBDII codes and the truck runs strong and smooth all the way to readline. The truck shows no signs of a problem.

I'm thinking the Torque app is reading the protocols wrong. If anyone has an early 1996 truck with a 5.7L vortec and the blutooth ELM327/Torque lite app, see if you get the same readings as I do for timing advance.
I'm not going to pay for Torque Pro because I have an Ultragauge coming in either today or tomorrow. I will see if it reads the same as Torque Lite.

I also have a new Delphi knock sensor/coolant temp sensor/195 degree thermostat standing by in case the Ultragauge reads the same as the Torque Lite app.
I'm still trouble shooting but anyone can comment with suggestions.


Edit: I forgot to mention that the truck came with a Hypertech 360202 hand held tuner with the programing installed. I have returned it back to stock settings but I still have the same issue.
It's possible that the hypertech could be the issue.

 

[96Z71ECSB]

Have the Ultragauge now. Nice little device.
The Ultragauge shows the same as the Torque app. The timing advance on my truck stays betyween -13 to -35 degrees.
I changed the knock sensor and the temp sender with no difference.
The truck still runs excellent and pulls 5000+ lbs with authority.
I wonder if both devices read the timing advance backwards? I'll have to see if I can check with a timing light.

I scored a untouched used computer for my truck for $25. Same exact computer/part #/programming code. It will take a week to get here.
I'll swap it in and see if it's the Hypertech programing that's the problem.
For now, I have a little research to do.

 

[96Z71ECSB]

Found the answer: This is from fullsizechevy.com

I've had that issue on my old stock '96 PCM, its not an accurate reading, some scanners don't read the timing advance on the '96-97 PCMs correctly and give a crazy negative number like that.
My hand held code reader that could view some live data used to read -45* advance at idle before I switched PCMs, after the switch, on a stock tune, the same scanner read +28* at idle, which is the verified correct reading...it has something to do with something internal to the 96-97 PCMs.
Unfortunately, I don't know if there is a way to fix it other than completely changing the PCM to a 411 like I did (however switching PCMs is mainly for other purposes).
Its best to just realize that the reading from your scanner is incorrect.


Problem solved.
I had a sneaky suspicion that the scanners were reading the timing advance wrong.
Like I said, my truck runs strong.
Maybe I'll invest in a 411, but probably not.
I plan on finding a 2500 or 3500 GMC truck with a 454 or 8.1L big block or possibly switch to a dodge cummins.
I need an 8 foot bed, 3/4 ton or better, with some big pulling power.

Then again, I may keep my '96.
I haven't really decided yet.

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