Not a big fan of people who ask for help but then know more than others. Correct, do your part and we`ll get it running good for you

 

Sorry, but I was not the member with the air "snorkle" issue. I was just responding to the request for an update by the member I quoted. I actually have done many things to attempt to remedy my SES issue. Much of it under the keen advice of Captain Hook & others. However, I was informing the forum of my experience with the change out in fuel blends here in Minnesota, which seemed to complicate the efforts to resolve the SES issue. Perhaps, my frustration with this issue caused me to be a bit hard on GM, but I think many will agree the Blazer is not one of their stellar achievements. I mean, as compared to my 1968 GTO.

However, your comments on the volt/ohm meter and OBD2 scanner are well noted and on my list of future purchases. After, changing out the two upstream O2 sensors, I was waiting to use up the tank full of winter blend gas and see what the computer thought of the summer blend. That process was interrupted when I had to fly to Florida and the vehicle sat for two weeks. As the SES light is now off again, I will continue my efforts to improve the dismal gas mileage in spite of new fuel injectors, distributor, plugs, wires, EGR valve, air filter, MAF cleaning, fuel pump, fuel filter, tires, etc. etc. Hey, it's finally summer now up here and at least I can work on this "devil" outside and in the sunlight.

 

I think you will find that the TCC is disabled when the PCM is in process of detecting failures (including your EGR code, even before the SES light comes on). This hurts gas mileage considerably. To check TCC, go a steady 50mph whan warmed up for maybe 10 seconds. Then tap the brake and see if RPMs go up. If no RPM increase, the TCC is not engaging. TCC is good for about 3-4 MPG at speeds above 45mph. Dragging brakes are another big time gas eater.

The point of my previous comments is that no actual physical diagnosis has ever been done - only scans at the parts store and shotgunning of possible parts based on forum comments. You have put a lot of parts in your vehicle, and your SES light is still coming on. Obvously this strategy isn't working for you, and none of the parts you put on were actually the cause. Need to stop changing parts, get the tools, and diagnose - or take it to someone who can.

Your computer really doesn't care about winter/summer gas blends.

12mpg vs 16mpg is about $600/year difference based on 10,000 miles driven and $3/gal. You can use that for justification of expenditures if you like!

 

You seem to have some good information here. I knew nothing about the TCC issue and will investigate that more fully. Seems like a logical concern. My intentions were to restore my Blazer to good operating condition and use it for light duty horse farm work in Florida where you often find yourself in "sugar sand". Of course, there is also fishing duty to contend with. I expected to replace most problematic parts anyway, as part of this project. If all went well, I was considering a second Blazer project I could leave in Minnesota for winter & recreational use. However, the SES/MPG issue is making that idea less desirable. I consider this a learning and tool accumulation project, but at times I think I'm in over my head. I will study this issue further and prepare for a non-rainy day. Thank you for the advice.

 

Glad you are taking my comments in the spirit they were intended.

IMHO the Blazers definitely have their specific quirks (intake manifold gaskets and injectors and wacky distributor caps), but other than that they are really very nice vehicles in general if maintained well and not screwed up by some idiot. But that is the problem with pretty much all older vehicles from the computer age. After all... what are we going to do? Go out and spend 30-40K on a new SUV to get 20MPG? Not me!! Personally I like their styling much better than anything new on the road today, and there are a ton of them to choose from at very reasonable prices. Just pick a good one (unlike me). I do know that I will be evaluating my next used car purchase with a wireless OBD2 scanner like Torque Pro during the test drive! I knew better, but I was a sucker for the condition of the body and interior.

Never liked Trailblazers or Envoys because they look like someone kicked them in the butt and the rear sits just a smidge too high for my tastes. Anyone else ever notice that about their styling?

 

Once I determined what the TCC is, I performed the check as you described. I did this several times. In all cases there was a brief increase in RPM's, but then a quick fall-off. Is this normal or should the RPM increase be sustained? My SES light has remained off now after several road trips of 50 miles or so.

I think I see what you're getting at regarding the Trailblazers/ Envoys.

 

Once you release the brake, the TCC hooks up again and the RPMs drop back to where you started. Sounds like yours is working. if the SES light comes on again, check the TCC again.

Hey Captain, can you give us an in-neutral wind coast down time from say 60mph to 30mph during calm winds for both your vehicles (which are different TC types but both known to get decent mileage in 2WD). We could use this to check for dragging brakes, etc, other problems with the two different transfer case types. Might make another good sticky and we could all compare coast down times with mileage being obtained for our individual TC case type!

Les

 

Regarding the Torque Pro scanner you referred to:

Is that a full featured OBD2 scanner or just a android phone app? Do you need a scanner first, then download the app. I am also seeing flash drive like devices available. I am confused as to what would be the appropriate tool for me that would allow me to related better with the "whiz-kids". What do you think of the AutoEnginunity device?

Thanks

 

The only full featured OBD2 scanner is the Tech2. The rest have varying amounts of functionality. I think the Torque Pro App with the BAFX Bluetooth ELM OBD2 adapter (from Amazon) gives you the most bang for the buck in an entry level device. Torque Pro has a lot of GM specific PIDs that allows a lot of additional things to be monitored. However it does not have the PID required to display cam position retard, and it will not trigger the crankshaft relearn procedure or display ABS, transmission, 4wd, etc codes. However I think it and the BAFX adapter are $30 very well spent. You can do a lot. Unfortunately this is for android only. I know of no equivalent combo for the iPhone or iPad.

I had to go to $150 Windows software/USB adapter to display cam position sensor and $300 Windows software/device to trigger the crank sensor relearn.

I still use Torque pro whenever possible because it's such a nice easy thing to use and configure custom live display screens.

 

Torque Pro is a smart phone app that is used in conjunction with a bluetooth enabled scan tool. I use Torque Pro on my phone with a Scantool.net OBDLink MX OBD2 adapter.

I also have Autoenginuity's Proline connector for more involved jobs and have yet to find a diagnostic chart that I cannot perform all of the steps on, including setting the CMP Retard and running through the CKP Relearn on my friend's '01 Bravada. It can access all of the serial bus connected systems (ABS, TCCM, SRS, etc).

I have used a few different PC based scan tools and so far, the Autoenginuity tool has been the most "bang for your buck" tool I have used. I will be selling it soon to upgrade to EFI Live's Scan & Tune setup. About twice the money as Autoenginuity, but gives me the ability to make changes to the tune on both my Denali and our Duramax work truck.