Bank 1 STFT showing lean

[FoMoCoSHO]

I wonder if there are enough differences between the '10-'12 and '13+ fuel systems to cause an issue with ethanol in earlier MYs.  That would be a dig to find that info!

The only difference I can find is the LPFP.

How are you achieving 2700 psi at the fuel rail?

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I have an excellent tuner.

I've been saying for a while that the fuel system is plenty capable but was being limited by Ford and it seems he figured it out

I know the conventional wisdom says FRP drops are normal.

But if you are commanding 2150 and only getting 1200, I would disagree. The last thing I want when boost and spark is spiking is rail pressure dropping.

There are all kinds of issues when your rail pressure drops, atomization suffers which causes wall wetting, which can cause knock.

Turning on torque management will help but not completely fix the issue.

 

[StealBlueSHO]

I wonder if there are enough differences between the '10-'12 and '13+ fuel systems to cause an issue with ethanol in earlier MYs.  That would be a dig to find that info!

The only difference I can find is the LPFP.

How are you achieving 2700 psi at the fuel rail?

Sent from my Nexus 6P using Tapatalk

I have an excellent tuner.

I've been saying for a while that the fuel system is plenty capable but was being limited by Ford and it seems he figured it out

I know the conventional wisdom says FRP drops are normal.

But if you are commanding 2150 and only getting 1200, I would disagree. The last thing I want when boost and spark is spiking is rail pressure dropping.

There are all kinds of issues when your rail pressure drops, atomization suffers which causes wall wetting, which can cause knock.

Turning on torque management will help but not completely fix the issue.

I have combed the forums and have pulled quite a bit of datalogs from other SHO owners. Every single one of them shows fuel rail pressure dropping around 4700 rpms after a shift change, some worse than others. There is one that is an exception and it appears to be a whole different beasty.. I am not sure which tunes or who tuned the various datalogs I have but they all have similar characteristics in the FRP...

I would imagin if someone has figured out how to "unlock" the software limitations on the HPFP to command 2700PSI or better then thats a significant modification. They could probably corner the market on ecoboost tuning.

 

[ajpturbo]

I wonder if there are enough differences between the '10-'12 and '13+ fuel systems to cause an issue with ethanol in earlier MYs.  That would be a dig to find that info!

The only difference I can find is the LPFP.

How are you achieving 2700 psi at the fuel rail?

Sent from my Nexus 6P using Tapatalk

I have an excellent tuner.

I've been saying for a while that the fuel system is plenty capable but was being limited by Ford and it seems he figured it out

I know the conventional wisdom says FRP drops are normal.

But if you are commanding 2150 and only getting 1200, I would disagree. The last thing I want when boost and spark is spiking is rail pressure dropping.

There are all kinds of issues when your rail pressure drops, atomization suffers which causes wall wetting, which can cause knock.

Turning on torque management will help but not completely fix the issue.

I have combed the forums and have pulled quite a bit of datalogs from other SHO owners. Every single one of them shows fuel rail pressure dropping around 4700 rpms after a shift change, some worse than others. There is one that is an exception and it appears to be a whole different beasty.. I am not sure which tunes or who tuned the various datalogs I have but they all have similar characteristics in the FRP...

I would imagin if someone has figured out how to "unlock" the software limitations on the HPFP to command 2700PSI or better then thats a significant modification. They could probably corner the market on ecoboost tuning.

There were a few mechanical limitersput on the hpfp that can limit the output that are easily changed with scalars in the tune...it seems even the 10-12 cars benefit from this also.

In addition to that, most if not all of the logs you have seen exibit the rail pressure drop at upshifts because of the inherent problem of load/boost spikes at the shifts....the load spikes deplete the rail quickly....control the load spikes, then u can control fuel pressure dips

Commanding 2700 at most times can be easy but i wouldnt want that much sustained pressure...2000-2200 is fine...the 2500+ is usually happening at run out times like when you have 2200 and then close the throttle


I have quite a few logs thati can post showing stable fuel pressure..maybe tonight i can post some screen shots

But obviously if boost is spiking to 240 kpa that will tax the fuel system 

 

[ajpturbo]

I just went back and read the thread...beeen a little busy and missed it but if you hit 22 psi and it was a spike that is extremely tough on rail pressure...1250 is getting low...i call 1000 danger zone but now with some of the changes ive made and seeing what is possible, i really see no reason at maderately aggressive boost of 16psi to tolerate less than 1800 ish

Also at low rpm its hard for the hpfp to make pressure because its basically a mechanical pump that needs rpm but if tuned well 15 psi boost at 2500 rpm is fine

Pm me ur email and ill look at a log if you'd like and i can tell you what i see....you most likely wont like it though....especially if you are spiking to 255 kpa....your spark tables most likely  arent even set up for that so you are relying on the knock sensors to pull the spark

 

[StealBlueSHO]

That all makes sense and I am curious as to how to control the load spikes at the up shift.. in short, my trims and AFR go to crap when the ecu tries to compensate for those spikes. I have talked to my tuner about them... maybe I will address it again.. and run some fuel cleaner in the meantime...



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[ajpturbo]

Something else, usually when rail drops and boost spikes that doesnt mean stft's go up....the ecu knows that pressure is down and knows that load has spiked...it cranks up injectors duty cycle.....when the ecu is adding fuel with the 02 sensors and trims it means something unexpected is going on....when pressure falls and boost spikes it knows that and makes the adjustments.

If you exceed what the map can see that can cause trims to rise because it DOESNT know that boost

I also wonder if your 02 sensor is bad

 

[ajpturbo]

If you are hitting 255 kpa then fuel cleaner wont help...you are running the piss out of it....control spikes with throttle like ford does

 

[StealBlueSHO]

Something else, usually when rail drops and boost spikes that doesnt mean stft's go up....the ecu knows that pressure is down and knows that load has spiked...it cranks up injectors duty cycle.....when the ecu is adding fuel with the 02 sensors and trims it means something unexpected is going on....when pressure falls and boost spikes it knows that and makes the adjustments.

If you exceed what the map can see that can cause trims to rise because it DOESNT know that boost

I also wonder if your 02 sensor is bad

Swapped WB O2 sensors out with new ones, didn't change a thing.

 

[ZSHO]

Have you checked out the Ford service OBD summary.  Z      http://www.fordservicecontent.com/ford_content/catalog/motorcraft/OBDSM1001.pdf

 

[StealBlueSHO]

Have you checked out the Ford service OBD summary.  Z      http://www.fordservicecontent.com/ford_content/catalog/motorcraft/OBDSM1001.pdf

That is a fantastic document, thank you!

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