Mazdaspeed DISI High Pressure Fuel Pump

Applicable Vehicles:
06-07 Mazdaspeed6
05-06 Mazda6 MPS
05-06 Mazdaspeed Atenza
07-13 Mazdaspeed3
06-11 Mazda3 MPS
06-11 Mazdaspeed Axela

The Mazdaspeed DISI engine has proven to be a remarkably stout and tunable platform. That being said we have found that it has one major limitation, the factory "High Pressure Fuel Pump" .

Unlike a traditional fuel injected gasoline engine that runs a relatively low fuel pressures, roughly 30-40psi. Mazda's Direct-Injection requires very high fuel pressure upwards of 1,600psi. This is accomplished with a mechanical fuel pump driven by the valve-train.

This mechanical fuel pump is unfortunately undersized for the engine. When we make more power from these engines it is not uncommon for fuel pressure to drop and the engine to run lean.

If you own a Mazdaspeed and plan to run any map higher than the base Stage 1 map you will need to upgrade this pump. It is important to monitor your fuel pressure!

There are several aftermarket companies that offer upgraded HPFP internals or even entire replacement pumps. We recommend AutoTech fuel pump internals, and there are offerings from Corksport and KMD as well. 

Here is a blog post for the HPFP internals if you are looking for more information on the subject:

https://www.cobbtuning.com/does-my-mazdaspeed-fuel-system-need-an-upgrade/

We have fuel pump internals available for sale on the website:

https://www.cobbtuning.com/products/mazdaspeed-fuel-pump-internals

If you see abrupt pressure drops, the car is also equipped with a pressure relief valve.  It is designed to begin to drop fuel pressure to prevent breaking seals or lines should the pressure go above 1850psi.  Keep in mind the valve works somewhat like a coolant thermostat.  This means that while it may begin to open at 1850psi, it will still not fully open until higher pressure.  In some cases it has been seen to fail from age and prevent fuel pressure from hitting the pressure needed to run properly.  If your in-tank pump and HPFP are in good condition that may be a good place to look for fuel pressure issues.