Issues with WOT low Fuel Pressure

[dsmiadh]

I am getting low fuel pressue down to 5psi on WOT which is then also causing error messages such as Cylinder misfire detected.

They are now recommending checking fuel system, but asking for a little guidance.

Have a 2025 DH HP with Tremec 6speed.

Current Modifications

Tune is being done remote by PBD for 93 octane.

I think they are doing a good job, but looking for a little direction.

Whipple Supercharger Stage 2 Comp
AWE switchpath Exhaust
Heat Exchange Upgrade
Dual IC Pump Upgrade
Billet 112M Intake Throttle body
Whipple Open Airbox Kit
Whipple Carbon Filter Intake Tube
ID1050-XDS Injectors
NGK Spark Plugs 6510 gapped at .024
UPR Catch Can and Clean side
Boundary Oil Pump Gear and Crankshaft Gear Combo
ARP balanced bolt
KPM 1000HP In-tank Fuel Module
Reische 170 degree thermostat
Stainless Power LTH catted

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[Q6543]

Sounds pretty simple, double check all the wiring to the new fuel system, make sure all connections and grounds are solid.

Did you replace and fuel lines on the car (front to back)?

if all that is good then pump is likely bad or something in their basket.

good luck, if a shop did any work they need to be doing this for you, if you installed it all check those

 

[dsmiadh]

Just so everyone knows this is what KPM is telling me.

Sent to PBD to make sure they know. Will keep you posted.

It sounds like the fuel pump may be triggering a shutdown event with FPDM (fuel pump driver module)

On the 2024 and up vehicles Ford superseded the old FPDM with one that has an over current function.

It’s speculated that this was Fords way of stopping people using BAPs and replacing fuel systems under warranty especially considering the fuel system recalls…..



If this is the case, your tuner will need to adjust a couple of tables back to factory values. The Whipple operating systems have the voltage request set very high to squeeze the most out of the OE fuel pump.





This table here is desired voltage to the fuel pump and should be set with factory values. However, if more is required from the fuel pump these numbers can be increased further but your tuner will have to do it incrementally to ensure it doesn’t have the same issue.

The Max voltage should reflect the highest value in the desired voltage table also.



Give this a go and let me know if I can be of any further help.

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