[j_k_auto]

As many of you know I am getting unforgiving fuel milage So I went and had my burban looked at today and everything is great except he said "timing sounds to quiet" I ask him what does he mean and he said normal timing should sound a little louder at idle. He said something is making the timing off a tad but if you rotate the pump it might throw a code. I told him thanks and paid the bill. Mechanic was around 6.5 for at least 15 yrs so I am pretty sure he knows a great deal in what he is telling me.

Anyhow I got my program up and running. What do you guys need to see so you can help me in figuring out what you see wrong.?

I can take pics,vids,and maybe somescreen shots but I can't get that to work. Let me know

thanks joe

 

[gmctd]

Take a mo' and read thru the other GMTDScan posts, then give it a scan.

ABSOLUTELY DO NOT ATTEMPT ANY COMMANDED ADJUSTMENTS - TIMESET, TDCO LEARN, CYLINDER BALANCE, etc.

Scan and observe, only, then post the data points.

 

[j_k_auto]

Here are my numbers as requested

I worked on this all day to get this done. Finally it is done This took a lot of typing to get it do...lol
Let me know what you think or if any more info is needed to help me out.
I am going to try and gather more info to help everyone out here. (something like a faq )
thanks joe

HERE IS THE LINK
http://home.dejazzd.com/jkauto/MY GMTDSCAN INFO.htm

 

[gmctd]

If you'll copy that to a file and post it here, we can analyze it here.

 

[j_k_auto]

Wow I thought there would be alot of input on this. I've been waiting to get my truck figured out since I got it. Now I finally got the program and spent a day getting all of this info put on the forum and no one has any sugesstions or input. SORRY BUT I AM DONE VENTING I JUST WANT TO GET MY TRUCK DONE.

WHERE DID ALL THE SCAN TECH GUYS GO? I GUESS THEY ARE ALL OUT SNOWMOBILING....OH WAIT THERES NO SNOW THIS YEAR.

 

[kena]

As to the gas mileage, have you checked to see if the brake system
is interfering with normal rotation of the wheels ?

Your values compare favorably to mine With the exception of:
Ignition Voltage - 13.3 to 13.5 (13.8)
Glow Plug Volts - .1 -----------(.01)
Battery Voltage- 13.2 to 13.4 -(13.8)
.
Did you take these readings with lights, heater and other current
hungary devices OFF ?

 

[j_k_auto]

lights on
heat front on low
Battery a little low (because on my pmd issue needs to restart now and again)

As far as checking my truck out I checked everything up and over this beast. This is what got me to get this program for the ecu so maybe I could get this figured out.
I wish I knew what is killing my mpg.

If you look at my homepage I did alot of checking and checking and I am getting no where.

 

[nickg]

Your TDCO should be closer to -1.94 NOT -.88, and your RPM reads low likely cause the TDCO is off.
I'm no expert in this dept

 

[kena]

The lights and heater ON would explain the lower voltages.
.
As far as the engine is concerned, all your sensor values look good. I cannot help with the automatic transmission values; mine is manual.
.
I would put the truck on a lift and spin the tires by hand to see if anything is binding.
.

 

[DavidPhillips]

Scan Tech

OK,


I have not did a TDC learn this time yet.

Last time I did one it said -2.02.

Any advise?

 

[kena]

The minus is telling you that the timing is before Top Dead Center and the 2.02 is the number of degrees. But the limits of measurement is plus or minus 2.02 degrees.
.
So it is telling you that you are at least 2.02* before TDC maybe more, because it is beyond the measurable range.
.
So now you must loosen the three IP bolts, retard the timing a bit and then snug the bolts down. Then crank it up and take another reading with the scan program.
.
If the timing is within range, you will read something less than -2.02*. If the timing is still out of range, you will read -2.02* and you must repeat the above steps.
.

 

[DavidPhillips]

So it would appear that the reading are as expected?

I am really wondering what is going on with the tdc because I am not getting an error code.

Later today I am going to attempt an adjustment.

 

[kena]

I had the same indication as you when I replaced my IP (-2.02*) and forgot to mark it first. So I retarded MM by MM and continued to do so until the -2.02* read something less. When it did, I knew I was in the ballpark and could set it to whatever I wanted within the range of -2.02* to +2.02*.
.
A good way to visualize it is just moving a 4.04* window around TDC.

.

 

[DavidPhillips]

Well, I'm going to rotate the IP and try to get 8.5 timing. And do a tdc learn.

 

[kena]

Don't forget to warm it up to operating temperature first.
.

 

[DavidPhillips]

Thanks

 

[j_k_auto]

I just want to make sure I got this right. What should be the 3 numbers here?

 

[DavidPhillips]

Here is what mine is after turning the IP.


I did get a code 88, it was not lighting the ses light but when I checked it this time it had the code.

Codes gone, all is good now.

 

[j_k_auto]

Anyone else have any imput?

 

[DavidPhillips]

You can check on the dashboard screen to see what you have now before attempting to set anything.

Post what you have before trying to set it.