• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

feed back TDCO from -0.18 to -1.94

Crankme69

New Member
Messages
1,901
Reaction score
15
Location
Illinois the Corruption Capitol of USA
I have been running my truck now about a week or maybe more with my TDCO reset from -0.18 to -1.94.

Couple of ya out there had asked me if it was worth doing & I promised some feed back after some miles with my impressions of this change...

Well unfortunately I did the TDCO update & as Murphy's law would have it, I also updated my air box to the K47 round style from the flat with new Amsoil nano filter, so not sure how much they interacted but my experience is very positive.

I just continue to be impressed with this 6.5TD, every little thing (like said by Matt) just continues to improve the drivability economy and power.

I am very pleased, yes it rattles a tad more in the morning when I leave for work...but it's a diesel right isn’t it supposed to rattle on cold startup? LOL I love that rattle!

Thanks to All for the suggestions & continued support much appreciated :thumbsup:

69
 
How much mileage gain did you see?

I am goin to do the same here in a couple weeks when I change out my IP.

Well that is going to take me more time to confirm...even with the 400+ miles I run a week, filling the tank is so dependent on how much time I allow for the foam to settle...

I will say that it sure did not hurt my MPG, setting at 475 miles on this tank now at 1/4. Gonna fill up on my way home tonight. It gott be avg right around 20mpg...
 
Foam's a bitch. Heres what I do.

Add Additive-
Fuel up till foam/fulll

Put additives away. Lets foam settle.
Full up again.

Check oil. Lets foam settle.
Top off.

That takes the bitch out of it and from the asshole behind you burning holes through your head with their eyes.

Then I write the mileage down on the reciept and put it in the spreadsheet.
 
Sounds about right. The only thing that it may hurt is in extreme heat the engine may run better with less advance.

Had you already put mandrel bent downpipe and xover on the exhaust? If you still got the 2.75" exhaust you still have some reasonably inexpensive gains to be had.
 
If this really helps mileage than I geuss its time to start looking up how to do this.
 
at least get TDCO read

If this really helps mileage than I geuss its time to start looking up how to do this.


I was on the fence about doing it also ....

Many members here told me I would be very happy with the outcome, they were correct. The motor just eases up through the rpm range with light throttle up to cruise now. I don't think I'm imagining it :eek:

At a min at least find out were the TDCO is operating at now, it may already be close enough...:thumbsup:
 
-1.8 to -1.94 should not be that much of a change, now -.75 to -1.5+ is night and day difference, once you get above -1.4+; beyond that net results will be vehicle/IP health individuality dependent results, -1.94 may not be the best, to "dial it in" for your truck, IMO one has to play with it to determine what is best for their trucks health.
 
I hear ya Doc I took mine from -0.18 to -1.94. I could not get it any less then -0.18 until I moved the IP...& it did not take much.

I may try to back it down to -1.5... for the winter but right now it seems to be in a very happy place. thx :thumbsup:
 
Nice work, Crankme... and thanks for the feedback! :thumbsup:

We appreciate when members check back in on stuff like this!

When Bill set my timing, it made a noticeable difference (according to my SOP dyno).

Funny thing was, even though I had added a chip, and a TM, and had more HP, I also found I got better mileage pulling my 5er. Like, instantly. The next day. (I was on holidays at the time, and stopped in Ellensburg for a tune-up on the way by... I was doing about a tank a day, so I got to see a quick spike in my graph.)
 
I was on the fence about doing it also ....

Many members here told me I would be very happy with the outcome, they were correct. The motor just eases up through the rpm range with light throttle up to cruise now. I don't think I'm imagining it :eek:

At a min at least find out were the TDCO is operating at now, it may already be close enough...:thumbsup:

Exactly!:thumbsup:
 
Sooo, why in the heck didn't GM set it there from the beginning????
Built in delayed failure to sell more parts after warranty?
WTF

Do I need to use a scanner, or can I eyeball it, say move it 1 or 2mm?

Possibly emissions and the possibility of cold start noise complaints would be my guess.

You need a scanner. You can't just move it a small amount with confidence without a scanner. The injector lines sometimes hold twist pressure, so just by loosening it it may move. Scanners are cheap for these trucks, and worth it.

Plus without a scanner, you have no idea where you are starting from, or where you end up.
 
Sooo, why in the heck didn't GM set it there from the beginning????
Built in delayed failure to sell more parts after warranty?
WTF

Do I need to use a scanner, or can I eyeball it, say move it 1 or 2mm?

The -.25 to -.75 set point was to meet emissions, and also why raising it beyond factory setting was never published/promoted by GM or put in GM manuals.

Yes with OBD-I you need a scan tool or Engh Motors OBD-I software to use you laptop to read & command TDCO learn. If someone has a OBD-II truck 96+ years, you need ability to read/clear codes/TDCO, and you can use the APP ko/ko method to command the learn.
 
Back
Top