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Old 03-29-19, 10:56 AM  
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Default How to correct High fuel pressure on a new build STI?

Hoping i can get some help/advise/insight from you guys.

Decided to rebuild the engine after a rod knock in my 15STI, now I m having an issue with high fuel pressure (58 PSI), idle gets bouncy after it is warm up. It is impossible to drive it without stalling all the time. The ECU has been flashed with a new basemap from a local tuner, assuming it was done correctly based on my mods.

At idle, the FP reads 58psi. The fuel sensor was installed on the FPR on the return line before the ethanol sensor. But when the supply line gets pinched the pressure can drop down to 42psi, idle will stable, and the WB 450 pump inside the surge tanks whines.

The radium surge tank has 4x -6 line connections, WB450 hardwired to the battery. Also a hard wire kit tapping the relay to the fuel pressure controller in the trunk.

BOV is tight shut at idle, no sign of vacuum leak.


Dom XT 1.5
1700 CC injectors
TGV deletes
Killerbee ELH
Killerbee oil pan and pickup
3 inch inlet
New built motor with forged internals
Cobb AOS

Cobb Flex fuel kit with fuel pressure sensor
Aeromotive Fuel Pressure regulator

Radium surge tank with WB 450
Aeromotive 325 in stock tank
Stock fuel rails

Any help will be appreciated.

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