if your HPFP pressure is low and you think your pump has failed. than it could also be your relief valve. to check this follow the instructions i give in the video.
signs of a bad relief valve are the following
1. Not hitting the commanded Fuel pressure
2. Low Air to Fuel ratio (AFR) reading close to 14.5 and not 14.7 when driving normally
3. High knock retard readings.
4. Lower than 400PSI fuel pressure when idling.
a data log like i explain in the video will confirm your problem! and of course if you have questions just drop them in the comments! or sent me a message!
The part you need on a Mazdaspeed3/6 is the following. L3K9-13-2J0 you can get the parts from the dealer but they may ask a high price or cant even get you the part and ask you to buy the whole Fuelrail. go to this website to get a local store [ Ссылка ]. i bought my part at [ Ссылка ]
if you live in Europe like i do and you want to save a bucket load of money i always advice to check the prices of OEM parts in the states cause even with import tax and shipping cost they are almost always around 50% cheaper than in the EU!
