[holdcop]

Ive posted before and tried a few new things to no avail.. going to reach out again..

My 2009 335i is on cts stage 2 twins, and while tuning my tuner docvu has advised that my lpfp pressure drops too low to continue revising. Between 6k and redline, this pressure can get as low as 40-50 psi. I was on a walbro 450 from precision raceworks, which I got flow tested by them as I thought I had a bad 450. Results came back fine. Car has a new ekpm3 from arc terminator. New fuel pressure regulator. Original pump has 80psi at idle, the 450 had 72ish psi at idle. Because of this, I thought the pump was not getting enough amperage to power a 450, so maybe my battery was going bad? Got it tested, it was bad, so I replaced it and the issue still stands.

I have not coded the ekpm3, I have been made aware that it should not be necessary for cars that already had an ekpm3, which mine did.

I did not code the battery yet, as I was made aware that coding the battery only affects how the car is charging the battery, not how the power is being used.

Currently on mhd stage 1+ so I can still drive it around, issue sometimes comes back at those high rpms.

Really not sure what to try anymore, any suggestions help

(I am having issues with o2 sensor codes and fuel trims, I think I may have either swapped the post cat sensors in the opposite banks or I am having some electrical issues elsewhere that may or may not also affect the fuel pump)

[lookalikehuuh]

What kind of fuel are you using? Do you know what kind of boost levels you are targeting with your setup? If you are pushing big power its likely you will need a dual walbro setup with a hobb switch that turns on at specific charge pressures to keep up with the flow requirements. This is especially true if you are on a E85mix since the flow requirements are much higher.

[holdcop]

Originally Posted by lookalikehuuh

What kind of fuel are you using? Do you know what kind of boost levels you are targeting with your setup? If you are pushing big power its likely you will need a dual walbro setup with a hobb switch that turns on at specific charge pressures to keep up with the flow requirements. This is especially true if you are on a E85mix since the flow requirements are much higher.

Nah man its just 93 targeting like 20 psi, stock pump should be able to handle it

[Sgop335]

Agree stock pump can handle that, esp. one w a clean fuel filter.
So why cant an “ upgraded” one..?
My lpfp dips too, way i see it, as long as rail pressure is strong and lamdas are good, and no fuel pump plausibility, what matters. Shifting at 7k.

[lookalikehuuh]

Originally Posted by holdcop

Nah man its just 93 targeting like 20 psi, stock pump should be able to handle it

That's why I asked because we didn't know any of this information and you didn't include it.

I don't know enough about Arc terminator EKPM3 to know if they are coded for higher output values, or if you need to code the EKPM so it knows its on a car with higher fuel demands. Do you know what its default coding is? Are they using strictly new EKPMs and the retrofitting or used ones?

Anyway, there was another thread where a member did some testing and actually found that EKPM2s had higher power outputs as compared to EKPM3. Also keep in mind there are apparently 2 revisions of the EKPM3, one of them supposedly being of lower quality design. Let me see if I can find you the threads on that.

[holdcop]

Originally Posted by lookalikehuuh

That's why I asked because we didn't know any of this information and you didn't include it.

I don't know enough about Arc terminator EKPM3 to know if they are coded for higher output values, or if you need to code the EKPM so it knows its on a car with higher fuel demands. Do you know what its default coding is? Are they using strictly new EKPMs and the retrofitting or used ones?

Anyway, there was another thread where a member did some testing and actually found that EKPM2s had higher power outputs as compared to EKPM3. Also keep in mind there are apparently 2 revisions of the EKPM3, one of them supposedly being of lower quality design. Let me see if I can find you the threads on that.

My thing is that I should not be facing ekpm limitations on a 450, thats a 525/dual 450 issue.. now if I need to code it due to the 2 revisions, i'd understand.. either way I am planning on learning how to code myself and if i have to do it anyways so be it

[lookalikehuuh]

Originally Posted by holdcop

My thing is that I should not be facing ekpm limitations on a 450, thats a 525/dual 450 issue.. now if I need to code it due to the 2 revisions, i'd understand.. either way I am planning on learning how to code myself and if i have to do it anyways so be it

Not true at all, go look thru the threads, tons of people have issues with Walbro 450 and EKPM2/3 even brand new ones. I had excessive current draw codes and overheating EKPM2 on my Walbro 450 pump until i actively cooled it. There really isn't that big of a difference in required current draw between the Walbrok 525 and the 450.

FYI A dual 450 REQUIRES a completely separate harness for the 2nd pump with a hobb switch to turn it on when boost builds.....

Anyway it sure sounds like you don't want my advice so I'll just see my way out of this thread.

[holdcop]

Originally Posted by lookalikehuuh

Not true at all, go look thru the threads, tons of people have issues with Walbro 450 and EKPM2/3 even brand new ones. I had excessive current draw codes and overheating EKPM2 on my Walbro 450 pump until i actively cooled it. There really isn't that big of a difference in required current draw between the Walbrok 525 and the 450.

FYI A dual 450 REQUIRES a completely separate harness for the 2nd pump with a hobb switch to turn it on when boost builds.....

Anyway it sure sounds like you don't want my advice so I'll just see my way out of this thread.

Im not trying to be hostile my fault if i came across that way, im just not sure how I am supposed to get around this issue if its an ekpm limitation. I have the same issue on my stock pump, so I am just not thinking its related to that.. plus the one I installed has active cooling