Fuel system adequate for HP but fuel pressure dropping on 2200hp system.

Is the fuel pressure dropping on your 2200hp VE-VF fuel system but the system is more than adequate for the pressumed HP?

what to check

• Has the fuel tank been filled before first start? On saddle style fuel tanks the primary fuel pump will always draw the fuel to that side.
  when fitting the 2200 and 2700hp systems the secondary pump may not have any fuel left on that side. filling up the tank will ensure fuel cascades over to the secondary pumps allowing them to fill the pots immediately and start syhoning between the primary and vice versa. This fill only needs to happen once and thereafter the tank can be filled to any level as normal.
• If there are calibration changes to make, ensure they are done correctly. You can find them on the Product Instructions page.
• Ensure battery and alternator voltage are as per manufacturer specification or better. Lower voltages can drastically reduce flow rate from the fuel pumps.
• Ensure all electrical connectors are secure, this includes making sure Anderson terminals are fully locked into the connectors, checking for any damaged or discoloured connectors.
• Ensure all earth points are clean and secure.

A quick test to ensure all pumps are switching on.

Giving the KPM PWM battery voltage to the “PWM enable” wire will switch all pumps on at 100% duty cycle (DC) and can be used to test total output and full operation of the fuel pumps.

Calibration and data log checks

If you have a 2010 onwards VE or VF Commodore or HSV which has the OE fuel system control module (FSCM) and have already confirmed with the above test that all three fuel pumps are operating then there could be an underlying issue with the vehicle.

If there is a problem with the FSCM of the vehicle you may be able to notice by taking a data log. If the “Commanded fuel pump duty cycle” appears to be sitting at 99.6% all the time even while idling this could indicate that something in the vehicle’s systems is not functioning correctly. If so then the KPM Fuel Systems PWM will be recieving a DC input but it will never reach the required DC to switch on the secondary pump module as it will be running from an open loop DC table in the calibration.

Possible causes

• Faulty FSCM
• Faulty OE fuel pressure sensor
• Damaged wiring
• Calibration errors (Refer to Product Instructions page for calibration notes)