2800 RPM Fuel Drop-Off

[2007 5.9]

Understood...my '07 has a 5733 designation and the '06 has a 5533...except for the middle 5 being a 7 on mine...it's close.

Any forseen issues with putting a 5533 in a 5733???

[TexasCummins]

I used to have this issue and fixed it unknowingly when I got the truck up to 3,400rpm today.

I went to the injection quantity pedal position to desired fuel normal and transient graphs and changed the mm3 value for 25%, 50% and 100% values for every rpm to 200.

[TorqueDieselLLC]

ok so after fighting this same fuel cut off i have a truck fully fueling to 4300rpm which is where i have the limiter set

could not get it there using the stock tune as a base

used SW9(non-4000rpm) as a base then ran my script over it and now it spins 4300 no problem at all, even tho the SW9 base tune was not capable of the rpm

my conclusion is that there is a table that we cant see right now that the SW9 is changing that is fixing the defuel

[chizwizdiz]

ok so after fighting this same fuel cut off i have a truck fully fueling to 4300rpm which is where i have the limiter set

could not get it there using the stock tune as a base

used SW9(non-4000rpm) as a base then ran my script over it and now it spins 4300 no problem at all, even tho the SW9 base tune was not capable of the rpm

my conclusion is that there is a table that we cant see right now that the SW9 is changing that is fixing the defuel

I'm curious to see what the EFI team finds.

[comnrailpwr]

X2

Spray & Pray

[bean]

ok so after fighting this same fuel cut off i have a truck fully fueling to 4300rpm which is where i have the limiter set

could not get it there using the stock tune as a base

used SW9(non-4000rpm) as a base then ran my script over it and now it spins 4300 no problem at all, even tho the SW9 base tune was not capable of the rpm

my conclusion is that there is a table that we cant see right now that the SW9 is changing that is fixing the defuel

Through extensive testing and data logging I too have come to the same conclusion, there is a table we dont have yet. Smarty files do not cut back on desired fuel but anything EFI I have tried will start cutting it back around 2400rpms and peaks power at 2800. This would include copy and pasting every single table from a Smarty file into a fresh EFI tune.

Pretty sure its a torque limiting table, if the % of maximum TQ PID goes over 100% it will immediatly start cutting fuel. The current TQ limit table doesnt do anything, you can put it at 1 or max it out and it changes nothing.

[dansdieselp]

We have our truck full fueling to 3,600rpm, but commanded pulse width drops off starting at 2,800rpm and can really hinder the power above 3k. Is everyone else seeing this same problem? In testing we've upped the pulse time and timing and it's neither a pulse multiplier table or pulse timing limiter. It has to be a max pulse vs rpm table as another form of engine protection.

[2007 5.9]

We have our truck full fueling to 3,600rpm, but commanded pulse width drops off starting at 2,800rpm and can really hinder the power above 3k. Is everyone else seeing this same problem? In testing we've upped the pulse time and timing and it's neither a pulse multiplier table or pulse timing limiter. It has to be a max pulse vs rpm table as another form of engine protection.

To me it also seems like a uS vs rpm limiting table....weather I command 3000uS or 5000uS, it always pulls back to 2000-2200uS at 2800......but commanded mm3 stays at 145mm3 the entire pull up to 4100rpm's.

~Les

[Dmaxink]

One of my issues was the pressure duty cycle... We could see the pressure start taking its effect as the dc% was going above 28. Being able to keep that at >24% allowed me to keep pressure and hold it and kept pulse (2450) all the way up to 3800 and then it takes a drastic drop. I have a customer logging a 3450 pulse this evening and i will report back the verdict. I have him a tune with stock DC and modified DC... I'm on vacation in panama, Fl so as soon as i get back on i will post the verdict! I will say without the necessary fp table modifications not timing, desired pressure, nor any other tables have had an effect on the limiter..the only one i have found in my case has been the duty cycle which is dependant on rpm. Again, i will report back. Thanks

[MQ105]

To me it also seems like a uS vs rpm limiting table....weather I command 3000uS or 5000uS, it always pulls back to 2000-2200uS at 2800......but commanded mm3 stays at 145mm3 the entire pull up to 4100rpm's.~Les

Interesting. My Commanded volume drops above 2900 rpm, with a corresponding change in duration. At times, the duration is a lot less than what is in the table. Also, I've seen the commanded volume go as low as 70mm3 at 3200 rpm and WOT.