New(to me) truck with unknown tuning.

[Rawze]

(07-21-2023 )mattdm Wrote:  Flashed the original Tune back and recovered the Multiplex settings. When I copied them into my CL10105 file the button functionality returned.

Currently working with Rawze on developing a proper file for the truck.

That is good.

you also sent me this e-mail some time yesterday though...

(07-21-2023 )mattdm Wrote:  Hey,

Finally had a few minutes to try this.
It doesn’t seem to be running as well as the stock file, its more similar to the bad delete file. Idle is rough and It stumbles on Decel and catches. Also there is an active fault for the multiplex response time(buttons don’t work). Any insite? What are the chances you would share your program with me so I can experiment with it a bit?

Thank you

The multiplex fault(s) are most likely the fact that you lost your dash settings due to not backing them up before flashing the stock file back in. A common mistake. If you go to advanced settings in Insite, and look under the Multiplex screen, it will tell you a detail of each of the devices that it is complaining about.

(as far as engine suddenly running rough goes) ...
Properly made de-mandate programming removes the internal engine load (engine always trying to make extra heat for the cans under the truck) that the stock file does to keep the aft-system warmed up.

Once that internal load on the engine is removed, and it is just idle free-spinning now, the turbo no longer spooled up any more to choke the exhaust, etc... if there are any engine issues (worn out head, leaky injectors, improperly reading sensors, etc), often they will be amplified and show up.

It is a CM2250, and the proper programming at this point around here is beyond well established, and has been properly made, then it is NOT going to be the fault of the programming itself if it is actually running poorly, stumbling, etc.

The engine is suddenly no longer under any internal load at idle any more, and if there is any instability in the injectors, excessive wear in the head, fuel system issues, etc.. it is now going to effect it more at idle.

I.E.> the engine runs differently after a proper de-mandate is done, and with far less internal friction/internal load, once those systems are removed and it is not being choked by high friction and the turbo not over-spooling at idle to make extra heat all the time.

=- I would suggest you start by doing engine tune-up work and start chasing down its actual mechanical woes to get the engine back running healthy.

things like ...
* Injector leak test, making sure it passes with flying colors. Shown in this video...
http://rawze.com/forums/showthread.php?t...3#pid75483

* Ensuring there is not a vacuum at idle at the IMAP sensor, like mentioned here:

Rawze Wrote:Remove the IMAP sensor from the manifold without disconnecting the wiring from it. Idle the truck, feather the throttle a few times hard to get everything to settle out, then slide the corner of a sheet of paper over the hole. See if the paper is mostly trying to be sucked into the hole.. or if it is mostly only fluttering up and down.. or if it is being mostly blown away from the hole.

- If it is being sucked in, the turbo is not spinning fast enough at idle, needs to be adjusted up,.. if it's being blown mostly away, the turbo positioning at idle can stand to be relaxed a bit, and fluttering only then the turbo is about where it need to be at idle, etc.

* Ensuring the overhead valves are adjusted properly.

* In an older engine with a lot of miles, or that has had bad programming in it for a while, it can also be loosing compression, or have leaky valve guide seals. Compression loss can be checked by block-plating the intake manifold, removing all the rocker arms, and then pressurizing the intake manifold to 30 psi and seeing if there are any intake valves leaking. Then do the same test on the exhaust manifold side of the engine.

-== I.E.> Actuial engine issues.

===========================

(subject of programming)...

The programming that I make DOES however have a moderately steep transition as it crosses below the 1,000 rpm range, and into the idle region. This is actually noticeable in sound and feel for the engine if someone pays close attention to it. It is also done on purpose, but it does NOT make the engine run rough, stumble, etc.

If the engine is actually running rough, stumbling etc. then it is actual engine issues, and the programming is simply revealing this now.

(The reason why I do this transition by default) ...
I do this for good reason. I own my own truck and know very well what it takes to make moneys out here long term. ... Most truck owners actually DO want this feature, rather than remove it. There are heavy benefits for transitioning the engine in this way down at idle, as it allows it to consume far less fuel at idle. For a lot of truck owners who have to idle at night, etc.. this is a significant gain in overall fuel economy and therefore profit.

That transition can certainly be removed just for 'sounds sake', as it causes no harm whatsoever, even long term, but the bulk of truck owners wold rather use 1/2 a gallon or less per hour, instead of about gallon+ of fuel for every hour of idle time. With the transition installed, the engine goes from consuming 40+ mg/stroke down to 28 or so. That is a fairly large drop in fuel consumption.

There are some exceptions though ...
- If someone has a heavily used PTO that runs at low rpm, say 900 or 1,000 rpm, (right along the transition point), then those settings can get in the way and it might need to be removed or set to a lower rpm. Other than that, it should normally stay.