Radium FPR RA Fuel Pressure Regulator Kit - Mazda MX-5 NB 99-05

Radium FPR RA Fuel Pressure Regulator Kit - Mazda MX-5 NB 99-05

Application: Mazda MX-5 NB (1999-2005)
Part Type: Fuel pressure regulator kit with RA-series multi-port regulator
Part Number: 20-1022

The Radium FPR Kit adds an adjustable fuel pressure regulator to the 1999-2005 Mazda MX-5, and works with all fuel pump hangers including the NB factory returnless system. The regulator mounts near the EVAP charcoal canister using OEM threaded studs.

The OEM feed line from the pump to the fuel filter is reused unaltered, with two new 6AN lines running to and from the regulator. A 0-100 psi gauge mounts beside the regulator on the feed line for adjustment, and a stainless steel SAE quick connect plug blocks off the TEE on the OEM feed line. No permanent modifications are required.

Key Features

• Hanger Compatibility: Works with the OEM fuel hanger (instructions cover bypassing the OEM FPR) and the Radium 20-1020 MX-5 hanger
• OEM Mounting: Mounts near the EVAP canister on OEM threaded studs
• Reuses OEM Feed Line: Factory pump-to-filter line reused unaltered
• Gauge Included: 0-100 psi gauge mounts beside the regulator
• Tool-less Adjustment: Turn the knob to set fuel pressure – detents give approx. 1 psi (±0.5 psi) per click, no jam nut or set screw
• Swivel Vacuum Port: 360° swivelling, double O-ring sealed vacuum reference port
• Interchangeable Vacuum Fittings: Four 10-32 threaded fittings: 5mm barb, 3AN male, push-to-connect and vacuum plug
• No Permanent Modifications: Bolt-in installation
• Fuel Compatibility: All petrol types (unleaded, leaded, oxygenated, pre-mix) plus methanol, ethanol and E85

What's Included

• MPR-RA fuel pressure regulator
• Fuel pressure gauge, 0-100 psi
• Stainless steel mounting bracket
• Anodised aluminium fittings
• SAE quick connect fittings incl. stainless steel plug for the OEM TEE
• Four 10-32 vacuum fittings (barbed, 3AN male, push-to-connect, vacuum plug)
• Hose clamps and hardware
• 6AN (3/8in) fuel hose

Optional Parts

• Radium Fuel Hanger, 89-05 Mazda MX-5, Pumps Not Included (20-1020) – Compatible Radium fuel pump hanger for single or dual aftermarket pumps

Important Notes

• Radium recommends using the vacuum plug to match OEM MX-5 constant fuel pressure
• Use a wicking, medium-strength threadlocker on the vacuum fitting
• A rapid fuel pressure drop after shut-off is normal for aftermarket regulators – pressure resets when the pump runs again
• Long cranking or slow pressure build-up is not caused by the regulator – it typically indicates fuel draining back to the tank from an internal pump module leak (e.g. venturi jet pump or missing check valve)
• Installation instructions are available in the Instructions tab

Vehicle Fitment

• Mazda MX-5 NB (1999-2005)

Not sure if this suits your vehicle? Email sales@coore.com.au and our team will confirm fitment.