Diesel Temp Tuning: 2 Steps Forward, 1 Back?

Hello,

Question for the "true" diesel enthusiasts:

When the engine is cold, the injection/fuel delivery start is advanced to compensate for the ignition delay.
This means that with a hot engine, the injection/fuel delivery start occurs relatively late.

Does this dependency also apply to the pure diesel temperature of an engine that is running at operating temperature?
Then, while the cheap, fake PD might increase the amount, it would also delay the start of fertilization, which in turn would reduce performance .

Hm,

You can connect a potentiometer to the MSTG and run the motor while logging the data.

Then, it should be possible to adjust the injection timing using the diesel temperature potentiometer.

m,,

dieselmartin wrote:

You can connect a potentiometer to the MSTG, run the motor, and log the data while it's running. Then, one should be able to adjust the injection timing by using the diesel temperature potentiometer.

Sure, but before putting in all that effort, I wanted to try to see if anyone knows it "off the top of their head" .

I can only report on the experiment involving temperature.

We adjusted the diesel engine temperature at the ASZ using a potentiometer, setting it between 60° and 140°.

Results in the DZR: 0 (zero) improvement, nothing at all...

We didn't check the injection timing, of course... something might be happening there... anyway, 10 cents doesn't work in our ASZ!

Cu Gremlin.

Hi Ulf!

Okay, I don't see any connection between diesel engine temperature and injection timing.
The diesel temperature is only used for density and possibly viscosity correction. For the injection timing, the engine temperature and intake air temperature are much more important in order to compensate for ignition delay.

Regards,
Alex.

Hi!

Hmm.. Okay, how should I manipulate the intake air temperature to achieve the earliest possible injection timing?

m3nx wrote:

Hmm.. Okay, how should I manipulate the intake air temperature to achieve the earliest possible injection timing?

The colder it gets, the earlier - I guess... which would mean a series resistance on the charge air temperature sensor.

Okay, I took some logs today.
Full throttle uphill in 3rd gear, from approximately 1200 to 4200 rpm, with the coolant temperature consistently at 90°.
Difference: The diesel temperature was recorded as 23°C in one instance and 117°C in another.

"Of course, I haven't always achieved matching speeds with the logs, but it's clearly evident that the start of the pumping process doesn't change between these temperature extremes."

@Gremlin, regarding the effect of diesel temperature tuning:
I didn't log the injection amounts, but the pump duration is included in the MWB 004 data.
And that difference is quite distinct between the two logs.
"Two engine speeds were recorded in both logs, which allows for a particularly good comparison (followed by the injection duration for diesel engines with 23 and 117 degrees of injection)."

2205 prm -> 17.9 / 20.9° kW
3402 rpm -> 20.4 / 22.9° kW

That "proves" that, at least in my engine, the 10c tuning works - which, incidentally, my own subjective experience also confirmed as a difference between the test runs.