So I posted back in December that I was having trouble with mileage in my 01 3500, and 6 months later I still am. Engine load at 65-70 usually hangs out at around 32-35 if the ground is flat, and the way my tune is set up (just like what is recommended and also based off tunes you guys have made) I'll cruise at about 15* of timing. I've checked everything for drag and still have found not brakes dragging or anything. Bout the only thing maybe out of line, would be at idle after it's warm it'll stumble a bit, but it still maintains the 6-9% load, I even saw it at 12% with the AC on.

 

So anyways, would I do any damage by setting my load limit higher to maintain the desired 19-20* at 2k? I've gone through multiple tunes and like I said before, I can feel the changes in the way it drives but man it does not change economy at all, period, and I'm getting fed up and I'm about to go back to my smarty....

  On 6/30/2020 at 6:00 PM, TheGreatWhite said:

Even if it's at like 34% load for an example?

Wow that is high...

 

Empty truck 20 to 22% at 66 mph or 2,000 rpm. 

31 foot rv at 17,300 pound gcw 33 to 35% at 66 mph or 2,000 rpm.

  On 7/1/2020 at 1:20 AM, Mopar1973Man said:

Wow that is high...

 

Empty truck 20 to 22% at 66 mph or 2,000 rpm. 

31 foot rv at 17,300 pound gcw 33 to 35% at 66 mph or 2,000 rpm.

It can get up there, keep in mind I'm pulling constant grades, and it's a dually with a flatbed that hangs off about 8in both sides...

Towing side should look at starting the timing on the low side, this builds your boost quick. About 4 degree step between bands. Then on load based opt for 3 degree. Builds back up power better allowing for some extra turbo spool.

  On 7/1/2020 at 1:46 AM, Mopar1973Man said:

Towing side should look at starting the timing on the low side, this builds your boost quick. About 4 degree step between bands. Then on load based opt for 3 degree. Builds back up power better allowing for some extra turbo spool.

I've got my current tune on 2 and I'm staying in that 20% with it creeping up towards 30% sometimes so we'll see how this tank does and I'll go from there.

 

Where would you recommend me start on the timing? 14*?

I'm playing with 4.5 step and started with 14.

  On 6/30/2020 at 5:24 PM, Me78569 said:

set your cruise load limit %5 above what your typical highway cruise load is. 

I'm not seeing cruise load limit on here.

maybe it's called light throttle load or something like that.   

  On 7/1/2020 at 1:13 PM, Me78569 said:

maybe it's called light throttle load or something like that.   

 

  On 7/1/2020 at 1:29 PM, Mopar1973Man said:

Gotcha, thank you gentlemen! I'm at work so I'll toy with it at work. I know I bumped it up but I didn't want to bump it up too much before consulting with the experts!

  On 6/27/2020 at 3:49 PM, TheGreatWhite said:

So I posted back in December that I was having trouble with mileage in my 01 3500, and 6 months later I still am. Engine load at 65-70 usually hangs out at around 32-35 if the ground is flat, and the way my tune is set up (just like what is recommended and also based off tunes you guys have made) I'll cruise at about 15* of timing. I've checked everything for drag and still have found not brakes dragging or anything. Bout the only thing maybe out of line, would be at idle after it's warm it'll stumble a bit, but it still maintains the 6-9% load, I even saw it at 12% with the AC on.

 

So anyways, would I do any damage by setting my load limit higher to maintain the desired 19-20* at 2k? I've gone through multiple tunes and like I said before, I can feel the changes in the way it drives but man it does not change economy at all, period, and I'm getting fed up and I'm about to go back to my smarty....

What kind of mileage you getting?

  On 7/2/2020 at 4:34 AM, Blueox01 said:

What kind of mileage you getting?

Anywhere from 14.2-15.2

  On 7/2/2020 at 9:55 AM, TheGreatWhite said:

Anywhere from 14.2-15.2

Low MPG you should be able to reach about 20 MPG. 14.2 MPG is what I getting with a 31 foot RV in tow. 

 

  On 7/2/2020 at 12:30 PM, Mopar1973Man said:

Low MPG you should be able to reach about 20 MPG. 14.2 MPG is what I getting with a 31 foot RV in tow. 

 

Yeah see that's why I've been scratching my head. I used to get 18-19mpg with my smarty and my 100s and then it started dropping and got to 16 and then I got the quad and it dropped all the way down to 14-15mpg and I kid you not no matter what I do tune wise nothing changes....

 

Could be injectors, but I'm not sure. Once warm it kinda has a catch in the idle, it's not bad, but still a catch.

Edited July 2, 20204 yr by TheGreatWhite

Somethig is reaching end of life if you are seeing that steady decline.  

  On 7/2/2020 at 12:50 PM, TheGreatWhite said:

Yeah see that's why I've been scratching my head. I used to get 18-19mpg with my smarty and my 100s and then it started dropping and got to 16 and then I got the quad and it dropped all the way down to 14-15mpg and I kid you not no matter what I do tune wise nothing changes....

 

Could be injectors, but I'm not sure. Once warm it kinda has a catch in the idle, it's not bad, but still a catch.

 

What is your engine load at idle? What is your idle speed on a digital display like Quadzilla?

 

If the idle RPM is above 800 RPM and engine load is serious low like 2 to 3% then your injectors typically are wearing out. 

 

Check for error codes or any P0216 codes. Lack of good timing will sink the MPG's. 

  On 7/2/2020 at 12:52 PM, Me78569 said:

Somethig is reaching end of life if you are seeing that steady decline.  

Well I figured it was the injection pump since it sat open in a shop for at least 6 years, but I bought a brand new pump and nothing changed. Has to be injectors, which I put in in Feb 2018.

  On 7/2/2020 at 12:57 PM, Mopar1973Man said:

 

What is your engine load at idle? What is your idle speed on a digital display like Quadzilla?

 

If the idle RPM is above 800 RPM and engine load is serious low like 2 to 3% then your injectors typically are wearing out. 

 

Check for error codes or any P0216 codes. Lack of good timing will sink the MPG's. 

6-9% at 800. A/C on I've seen it up to 12 at idle.

Might be worth pop testing but looks good with that engine load and RPM. 

 

Valve lash?

  On 7/2/2020 at 1:53 PM, TheGreatWhite said:

6-9% at 800. A/C on I've seen it up to 12 at idle.

Do you mean it idles 1200 rpm with the AC on?

  On 7/2/2020 at 2:55 PM, dripley said:

Do you mean it idles 1200 rpm with the AC on?

Now engine load % is up to 12% with A/C on. 

  On 7/2/2020 at 1:57 PM, Mopar1973Man said:

Might be worth pop testing but looks good with that engine load and RPM. 

 

Valve lash?

Set valve lash a year ago, and it wasn't that much off when I did...

  On 7/2/2020 at 2:55 PM, dripley said:

Do you mean it idles 1200 rpm with the AC on?

800, like Mike said. I probably should have specified, 12% load at idle with a/c on.