Suggestions??

[Denaliquadrasteer]

23-01-14 09-32-55.hpl2007 Dodge 2500 5.9 Cummins Stock Revised.hpt23-01-14 08-00-03.hpl

So, this tune is very close to stock. The stock tune on my truck got about 21mpg at 50mph. I am trying to figure out why it drops to 16.5 when I just pull the post injection event. Also, why it drops to 17mpg at 65mph the way it is. The I am looking for the best MPG I can get, lower rail pressure, and remove the post injection event all in the hope to keep wear on my new injectors down. I have 6 new Bosch injectors I installed about 10,000 miles ago along with an Airdog and a separate Cat 2-micron filter. I am starting a new job further away and want to keep my beloved truck. I live at sea level in SC so mostly flat ground. I'm not looking for any kind of hand out just some direction. Thank you all in advance for being an awesome community and wealth of knowledge. Just to add the truck is a 2007 5.9 Megacab 4x4 Laramie with Auto transmission and soft tonnue cover.

[Jim P]

If you remove post injection the ecm takes that fuel quantity and puts it onto the main fuel injection. Not having that post event later in the cycle reduces heat later in the cycle which slows down the turbo speed. Because the main event fuel quantity is being changed when the post event is eliminated and the slowing of the turbo speed, you need to adjust for that. Log to determine where in the tables the engine is running at for your target operating range and adjust timing, rail pressure, etc till you achieve your desired results.

[Denaliquadrasteer]

Ok just a couple questions to make sure I'm understanding.
So to effectively lower rail pressure I need to raise pulsewith to get the same amount of fuel at that same point in time?
Can I add the main and post pulse together then retard the timing in that area to eliminate the need for post event but keep the heat in the cylinder?
Is it easier to keep the post event in?
If so what would be the estimated wear?
Would it possibly be a third the overall life of the injectors hahahaah.
Sorry for all the questions its just very stressful to flash this truck. Have to disconnect the intake heater, abs motor, and fuel pump then hope and pray it completes and doest seize up and brick the ecm hahahaha. My stomach flips during the process after the first time it failed after an erase!! Jim P you saved me 2 years ago with that thank you again!!

[Denaliquadrasteer]

Am I way off? I've been away from the dodge tuning for a couple years and just getting back into it. Guessing I need a refresher....

[JaegerWrenching]

Lowering rail pressure and doing nothing else will naturally increase the actual PW because you will still be asking for the exact same amount of fuel to be injected, except it'll be done at a lower rail pressure. The ECU looks at the PW map and say instead of needing 1000us i now need 1200us. Think of trying to fill a cup of water under the sink with the faucet on full blast vs a pencil size stream, your goal is to fill the cup "desired fuel amount" the only thing that changes between a full blast faucet and a small stream is how long you have to hold your cup under the faucet before it's filled up.

[Denaliquadrasteer]

JaegerWrenching, I didn't realize the ECM was going to compensate like that. So is there a way to increase economy on lower rail pressure? Or do you compromise on high rail pressure with higher injector wear for fuel economy...... or is that where fuel timing comes in. Lower the rail pressure, the computer compensates the pulsewidth then I change the timing (retard with hopes to use more of it) to still get the most out of the fuel injected.