[g22rmr]

I have a full bolt on n54 and I've surpassed the limit of what my stock low pressure fuel pump can deliver. Logs show fuel pressure dropping dangerously low almost as soon as the boost comes on. I'd like to run some E85 mixes but the LPF pump can't handle my engines requirements on 93 octane alone. I have just under 90K miles now and I've been modified since 37k miles. My turbos don't currently have a wastegate rattle problem, but I'm okay if they die in the next 20k miles as I really only take this car out for fun once a week. At that point the prices on the single turbo kits should have come down and I'll go that route.

So I'm looking at the Fuel It packages and I see the standard "stage 2" upgrade can cause the pump control module to overheat. So they recommend leaving the stock pump and adding an additional pump next to it. However the secondary pump cannot be active full time and therefore requires a trigger to turn on and off. They told me JB4 can handle that functionality, however all I see on my jb4 app is water meth injection triggers.

Is there an option that doesn't burn out the pump control module, that doesn't require an external trigger like a hobb's switch? Or where exactly in the jb4 is the function to enable the second pump past XX PSI? I'm pulling my hair out trying to come up with a solution for this.

[Jeef]

Just buy the stage 2 bucket setup from fuel it and you'll be fine. Not sure where you are getting the info from.

[g22rmr]

It's right there in RED on the Fuel It page for the stage 2,

Upgraded pumps pull more current, so if your EKP (LPFP control module) is weak, it may overheat causing it to shut down and need to be replaced. If this is a concern for you checkout our Stage 3 fuel pump upgrade kits that retain the stock LPFP and add a secondary pump.

[Jeff@TopGearSolutions]

It's mentioned for liability purposes. The issue isn't all too common.

I'd recommend reaching out directly to Fuel it about your concerns.

[Jklad]

Originally Posted by Jeff@TopGearSolutions

It's mentioned for liability purposes. The issue isn't all too common.

I'd recommend reaching out directly to Fuel it about your concerns.

Is he talking about the fuel regulator that sits inside the other half of the gas tank, accessed via the other rear seat? If so that part is less than $200 so you can easily and cheaply replace it if youre worried about it.

[Jeef]

Originally Posted by g22rmr

It's right there in RED on the Fuel It page for the stage 2,

Upgraded pumps pull more current, so if your EKP (LPFP control module) is weak, it may overheat causing it to shut down and need to be replaced. If this is a concern for you checkout our Stage 3 fuel pump upgrade kits that retain the stock LPFP and add a secondary pump.

Stage 3 runs the same pump, just 2. 1 is triggered via hobb switch or other methods

[g22rmr]

Originally Posted by Jklad

Is he talking about the fuel regulator that sits inside the other half of the gas tank, accessed via the other rear seat? If so that part is less than $200 so you can easily and cheaply replace it if youre worried about it.

https://www.fcpeuro.com/products/bmw...SABEgJjx_D_BwE

16147229173
Price each: $314.22

Yes because I totally want to continually burn those things out and have to keep replacing them....

[g22rmr]

Originally Posted by Jeef

Stage 3 runs the same pump, just 2. 1 is triggered via hobb switch or other methods

Could you explain to me exactly where this functionality is in JB4, either dashboard input or on the mobile app? Thank you.

[Jeef]

Originally Posted by g22rmr

Could you explain to me exactly where this functionality is in JB4, either dashboard input or on the mobile app? Thank you.

You need to wire the pump to trigger off the jb4 if you want to go that route. I believe nitrous settings are used for it.

I honestly would just go with a hobb switch so you don't have to rely on jb4 for the 2nd pump. In case you ever move to flash only or whatever it may be.

[MSully96]

I'm curious about this as well. I'm getting ready to do FMIC and inlets and I'm sure at some point my lpfp will start to die and I will have to upgrade. Definitely don't want to have to worry about the control module failing..

[Jklad]

Originally Posted by g22rmr

https://www.fcpeuro.com/products/bmw...SABEgJjx_D_BwE

16147229173
Price each: $314.22

Yes because I totally want to continually burn those things out and have to keep replacing them....

Oh this is a different part than what I was referring to. 11 years on this forum and haven't read about this failing, I guess anything's possible though.

[Rob09msport]

I thought we are good for 20 amps and that is why dw400 is no go cause to taxing but the 450 is fine plus bucketless I thought puts less load on regulator.