Boost - Fuel Cut Table

[Dano2010]

Can anyone confirm how the ECU Fuel Cut occurs? Does is cause your CDFP PSI to drop or is it controlled elsewhere? The reason I ask is in the attached logs you can see my Fuel PSI drop right after I have hit the 21.03 PSI limit in my Boost-Fuel Cut Table AND my Throttle % appears to drop as well during that time which is targeted just below the 21 PSI Boost limit in the Boost Throttle Close table.

Any comments would be GREATLY appreciated.

P.S. I dont have upgraded CDFP yet but until I started sustaining higher boost my CDFP PSI was always 1650-17xx

 

[COBB Tuning]

Your log looks ok, but I would look into that fuel pump. If you are dropping off fuel pressure that hard at WOT, it might be a sign that it is starting to give, the "cut" you are feeling is actually a lean misfire. Get that pump upgraded ASAP.

 

[Dano2010]

Thanks Travis!!!

I am waiting for PTP to get more parts in and I'll have a new pump.

I have been modifing your Stage2 + MSCAI2 91v 105 map to try and keep the boost from tapering off so much - to 16.xx psi from around 4800 up, by changing my Throttle- Request Load xx Gear tables. Maybe when I get my CDFP fixed things will improve?? 4th gear looks good but 3rd still falls fast.

Anything you can add would help greatly.

P.S. TMIC is on the way as well.

Thanks again for all of your's and Cobb's hard work on this ECU. I know you guys go much unappreciated!!

 

[Dano2010]

oh an just FYI I am not "feeling" any cut. The engine continues to run strong and AFRs actually richened on some logs during the drop off, then when I returned home to look at the logs I was very surprised. I just thought that maybe the ECU was cutting fuel at the CDFP by changing something with the solenoid. I am still learning.

 

[COBB Tuning]

There isn't a whole lot you can do to prevent boost taper, it's really just the physics of the turbocharger. There is no "fuel cut" in the way that you are describing, it really is just your fuel pump going out. Good luck!

Travis
COBB Tuning

 

[Dano2010]

Ok, Thanks again!