Btw, I'm going to go ahead and get the parts from home depot because I have some of the part already for the pressure gauge. I'll get a pressure reading for a dead end hookup before I start replacing parts.

 

Glad to hear it. Until then.......

 

RacerX is not wrong in what he is saying, but we apparently simply disagree on what the the next step should be.

However, if you would like to utilize the OBD2 app as he describes (or even just for interest), it appears to me that in Dash Command you can get a plot of a sensor function by setting Gauge Type as a Square Line Graph. I have not tried this yet as I am sitting in my office without my vehicle. Indeed, Dash Command has some of these plots already configured in the default gauge screens and you can use the edit function to look at how they are configured. You can also data log specific sensors with most of these apps and I have seen that option pop up in Dash Command somewhere. Remember, I just recently got Dash Command to see if it would also do cam retard - bonus seems to be that it works on early OBD2 Blazers (where Car Gauge Pro does not). I really haven't looked at it all that much yet as I have become very comfortable with Car Gauge Pro for my vehicle.

But I can tell you that if you want to look at oscillations of O2 sensor voltages with a bluetooth OBD2 device, it is best to reduce the number of things being monitored so the sampling rate is maximized for that sensor and that a plot is very necessary. This means not many gauges on a page. With the old BAFX OBD2 device you have about 20-30 scans/second to spread amongst all monitored gauges. Voltages change very fast back and forth (or at least they should) over a range of voltages. Same thing with short term fuel trims - they oscillate and you are looking at a range of values that change very rapidly. If you just look at the numeric values displayed on a digital gauge, you can be very misled as they are not updated at the same rate as a plot.

RacerX - didn't you buy the new BAFX Bluetooth device? If you have Torque Pro, it will tell you the observed scan rate. This I would really like to know - as that is the real reason for buying the BAFX over the others. Have they maintained their quality with the new unit?

 

Graveyard, if you were seeing the misfire counters evenly across all cylinders, monitoring O2 sensor voltage graph, short and long term fuel trims only on bank 1 will give faster updates and show the waveforms from the O2 sensor better. That's because ....

Les is right on the money with the update speed. I finally did upgrade to Torque Pro, and with the newer BAFX adapter, I'm seeing only 20 ish PIDs/second best case when the android device has been used with other apps (sometimes as low as 4 PIDs/second). If I reboot (power off completely, and boot up where it shows all the boot time logos and messages), and go directly to Torque Pro without using any other apps, I get 24-ish PIDs/second, and if I reboot, turn off WiFi, and stop a few processes I'm pretty sure I don't need, I get it up into the 29.x PIDs/second range. These apps seem sensitive to the Android device performance and other apps, too. Those numbers are when connecting to a 2006 Jeep with a 4.7L V8, not a Blazer. It's possible the ECM is a factor in that performance as well. On the Jeep, I'm seeing 11 to 12 "waves" in 10 seconds on the O2 sensor traces, and if I do all 6 of the gauges I suggested in Torque Pro, It barely maintains a recognizable trace of the wave forms for the O2 sensor voltages.

I'm seriously considering upgrading my android device (getting a new one for general use), and dedicating this one to "scan tool" status and stripping it back to factory defaults, possibly even removing or disabling some of the apps it came with.

BTW, I probably need to put the O2 sensor graph thing in my "tip of the week" soon. Those two graphs (only those graphs) on screen are the best tool ever for finding vacuum leaks when spraying intake cleaner around gaskets and O-rings and seals looking for a leak. Cleaner through a very small vacuum leak will disrupt the normal rhythm of the sensors at idle. You can find leaks that won't even audibly increase engine speed.

 

Thanks for that info on the refresh rate for the new BAFX adapter. It seems reasonable to me, and as good as the old one. With the old BAFX I got in the 20's on my 2001 Blazer (J1850-10.4 protocol only) and high 30's on my 2008 Ford Ranger (CAN protocol only). So I can attest that communication protocol and/or manufacturer can have an effect as well. 2006 Chrysler products is 65% J1850-10.4 / 35% CAN - so your Jeep is a toss-up which one (but I'm betting it is J1850-10.4 like our Blazers based on your reported speed.
FYI
http://www.alpha-bid.com/media/Share..._protocols.pdf
A USB hardwire OBD2 adapter is lightning speed in comparison to Bluetooth, even on the same vehicle - but the Bluetooth is SO handy and the apps are SO inexpensive and convenient!

p.s. I tried setting up the cam retard PID in Torque Pro from that forum you linked to and it always read (0.0) on my vehicle when I knew it was 0.3 on several other softwares including hardwire Windows software. Did you have any luck with it? Also don't you also have a 2006 Olds Bravada vehicle? Can you verify that Car Gauge Pro did or did not work on your 1996 for extended GM PIDs? What about Torque Pro?

 

Hey Guys,
I haven't abandoned ya but I do have to take a break due to personal issues. My Dad is not doing well and the Blazer is on the back burner for a short time.
Thanks for the help so far though, and I may be asking some questions about creating the gauges for checking sensors and stuff during a little down time.
Later

 

We will be here when you get back. Best wishes for your Father's rapid return to health.

 

Thanks

 

Graveyard, I totally understand. Family first, and my thoughts and prayers are with you for your dad.

Les, I haven't been near the Oldsmo-Blazer in several weeks. I've also had some "personal challenges" occupying a lot of my time, and keeping me close to home. The Bravada is at a friend's house now, with a brand new front cover installed, but with the harmonic balancer still off, and the new water pump, fan clutch and fan shroud not yet installed. I'm hoping to get back to it in the next week or two and get it back on the road.

I did post a follow up over on the Torque-BHP forums about your experience with that custom PID. I thought that was a little too "app specific" and "techy" for this forum at this time.

 

Whenever you get a chance I would be interested in the info. I also posted on the Torque forum in that same thread about my experience with that PID info. Haven't been back to look, though. Later.....