Fuel Pump Max Duty Cycle

[FiveLeeter918]

Was doing some logging to day working with knock and spark timing on my E20 tune, and decided to step up to E30. Did a pull and car felt like it lost power so I shut it down and looked at the log and it appears to have pegs the fuel pump duty cycle at 50% and just flatlined there.

Is 50% the max of this pump, or is that just another limit switch to overcome for tuning?

Thanks!

 

[FoMoCoSHO]

Low pressure or high pressure?

 

[FiveLeeter918]

assuming low pressure. The curve in the background is my fuel rail pressure. You can see it take a huge dive when this maxes out, but can't see me being maxed on the high pressure pump...

 

[SHOdded]

Assuming there is a hardware problem, have all recalls been done on your SHO.  Specifically FP and FPCM, if applicable.

 

[FiveLeeter918]

Just bought the car in June. Didn't mention anything about recalls and SYNC maintenance reports show I'm up to date.

 

[FiveLeeter918]

yea just logged in to the Ford Owner site and it says I'm up to date on everything, just notes that the Service Warranty on the SYNC system has been extended.

 

[ajpturbo]

Yes .50 or 50% is max..sounds like you are fine on that...sometimes .49 is max for the low pressure..its like that on mustangs too

But not sure why you felt the hesitation

 

[FiveLeeter918]

after more research (and a lengthy discussion with FoMoCoSHO, it appears I was commanding too rich in my fuel tables. Had been commanding 0.80 across the board. Switched to his recommendation and the fuel pump is back down to ~0.46 and we're making power again.