[holdcop]

Im on my 5th tune revision on my hybrid turbo e93 n54, and running into an issue where lpfp pressure drops from 70+ to as low as 42 after 6000 rpms. As a result rail pressure is also tanking. I checked the quick connect fittings, they look fine and the clips are in tact. I put a stage 2 precision raceworks non-modular bucketed lpfp into the car. The walbro 450 it came with should be more than enough. Not really sure what to do about this other than pull the lpfp again and check it out. Anything I should look for specifically? Log attached: black line is rail pressure purple is lpfp and green is rpms

May also be worth noting i think theres a clogged valve on my gas tank as gas pumps click a bit early when fueling. Also, i get the 2aaf dme code

[oVeRdOsE.]

I dont think the air pressure in the tank can cause this, it might but I doubt. Since I own my bmw I need to fill the tank with the gun upside down, and running a big turbo.

What fuel and max boost pressure you are running?

Might be the EKP letting you down if your is stock.


I had to passive and active cooling mine,

[holdcop]

Originally Posted by oVeRdOsE.

I dont think the air pressure in the tank can cause this, it might but I doubt. Since I own my bmw I need to fill the tank with the gun upside down, and running a big turbo.

What fuel and max boost pressure you are running?

Might be the EKP letting you down if your is stock.


I had to passive and active cooling mine,

93 octane, this tune targets 20 psi.. i was thinking it was a flow rate issue because each log looks exactly the same only dipping right at 6k rpms, even when i take them back to back while still on the road. If it was the ekpm overheating it would gradually get worse no?

[oVeRdOsE.]

Originally Posted by holdcop

93 octane, this tune targets 20 psi.. i was thinking it was a flow rate issue because each log looks exactly the same only dipping right at 6k rpms, even when i take them back to back while still on the road. If it was the ekpm overheating it would gradually get worse no?

20psi on 93, even the stock fuel pump should be fine.
I ran 21 psi on 91 + meth for a long time on the stock lpfp, and the pressure was constant. I,ve changed it for maintenance, and trying to push the car more.

I was under impression the EKP simply stop working when it's tired to push a 450, but maybe it can do this too.

Not an expert. jb4tech or spool street might have the answer, I do remember seeing many thread on that.

[iqraceworks]

Is there a change that your 450 LPFP could just be getting worn out? Do you know it's a real Walbro 450, or some china copy?

And yes...it could be an EKP issue, but I thought that when they overheat...they just shut the LPFP completely off?

[holdcop]

Originally Posted by iqraceworks

Is there a change that your 450 LPFP could just be getting worn out? Do you know it's a real Walbro 450, or some china copy?

And yes...it could be an EKP issue, but I thought that when they overheat...they just shut the LPFP completely off?

Nah its a precision raceworks setup, i pulled it earlier to doublecheck everything. Over the phone they told me it could be fuel filter. Just replaced the whole regulator assembly, idle psi is now higher im gonna take another log here soon

[oVeRdOsE.]

Originally Posted by holdcop

Nah its a precision raceworks setup, i pulled it earlier to doublecheck everything. Over the phone they told me it could be fuel filter. Just replaced the whole regulator assembly, idle psi is now higher im gonna take another log here soon

run it while peaking on the fitting. You might find the main fitting pissing fuel back to the tank.

[holdcop]

Originally Posted by oVeRdOsE.

run it while peaking on the fitting. You might find the main fitting pissing fuel back to the tank.

The quick connect thats on the tophat? Thats solid, ive ran it with the cover off to confirm it wasnt leaking out from right there

[holdcop]

New log below, lpfp actually gets above 90 psi like it should with the new regulator but is stil dropping near redline.. considering epk overheating now? Would I have other issues than a decreasing psi?