Lpfp psi drops under wot

[JayN54Sosa]

My lpfp psi drops from the high 60s to the low 30s under WOT. I’ve went through 2 offbrand OEM pumps and now on a OEM VDO brand pump. My first old one was terrible and I admit it’s fixed a lot of the issue with new ones. However I still sometimes can get a solid pull in but mostly it’ll dips super low and my car goes in limp mode.

New HPFP, new LPFP, spark plugs, coilpacks, injectors seem to be fine, lpfp sensor is fairly new.

car is 2007 335i e92,msd81 upgrade DME, vrsf intercooler, catless downpipes, dualcones, chargepipe and blowoff valve, mhd stage2+.

I just recently am running e30 mix and it does pretty good with it and I’ve done some successful pulls but it’s almost the same as if it’s pump 93, still dips low sometimes and goes right back to normal after my pedal input is like 10-25%

 

[ShocknAwe]

Helps folks if you post a log with all the standard parameters.

 

[NoGuru]

Yeah, log will help. Also where were these pumps purchased from. If you say Amazon or Ebay you can be sure they are counterfeit.

 

[GreyNBlueE92]

Fit a walbro in there and you should be good. Factory pumps can barely keep up with E mixes unless your boost is kept low

 

[digitalashley]

Not sure what pump you have is rated to do flow wise but if it's not enough like a walbro 450 for example maybe try one of those and. If your not using factory stuff to connect the pump up leaks in lines will cause psi drops. Also which ekp module do you have 2 or 3 that's another thing to keep in mind if your pump has high current draw it may be causing issue with heat at the ekp module. I doubt this is a current issue with your setup but something to keep in mind if you upgrade, as they can get very warm as you may see online

 

[JayN54Sosa]

Yeah, log will help. Also where were these pumps purchased from. If you say Amazon or Ebay you can be sure they are counterfeit.

I’m running a OEM VDO one off fcpeuro, which couldn’t keep up with 93 octane OR e30. My other 335i is perfectly fine but this one has been a non stop battle for me

 

[NoGuru]

Upload a log to Datazap.

 

[Torgus]

Fit a walbro in there and you should be good. Factory pumps can barely keep up with E mixes unless your boost is kept low

This.

OP, I am surprised you spent the time to put in a new factory pump. Throw in a walbro. The factory pump does 'ok' but nothing impressive. You can easily run out of pump on factory turbos.

 

[JayN54Sosa]

Upload a log to Datazap.

datazap.me | Jayn54Sosa | pull after rear turbo wg vac line repair mhd stg2+ e30 map 18psi

datazap.me

Check the lpfp and watch down it dips

 

[JayN54Sosa]

Helps folks if you post a log with all the standard parameters.

datazap.me | Jayn54Sosa | pull after rear turbo wg vac line repair mhd stg2+ e30 map 18psi

datazap.me

 

[NoGuru]

WOW, that is bad. Replace EKP

 

[JayN54Sosa]

WOW, that is bad. Replace EKP

and if that doesn’t work?

 

[ShocknAwe]

Is your pressure flatlined? Can't tell on my phone looks like there's no variation.

 

[digitalashley]

I don't know jack. But I had fueling pressure issue on ijeos car and this is definitely much more drastic. I would suggest after looking at that log you need to swap your ekp with the other car you have and see what happens just plug it in and Then log. If it's the same I'd say it's your regulator or lpfp sensor or a decent leak inside the tank. But I doubt that as it's stock the pump doesn't sound weird right? And it was an pressure issue is why you replaced it?Ekp seems more likely as it's just 30psi the whole time you have throttle down. But I'd swap the ekp over first to test then check for leaks if that didn't help . And hopefully someone else chimes in with some good info as well. But yeah definitely be careful. Any errors?

 

[ShocknAwe]

Either EKP or the actual LP sensor/line.

It's not completely flat like I first thought now that I see the chart on a screen, but damn close you only have like 2psi variance and it's at 30psi which is 20-30psi past failure.

 

[JayN54Sosa]

Either EKP or the actual LP sensor/line.

It's not completely flat like I first thought now that I see the chart on a screen, but damn close you only have like 2psi variance and it's at 30psi which is 20-30psi past failure.

I never can find the actual part numbers for the lp lines

 

[ShocknAwe]

Realoem and the hard line has an integrated sensor. Got mine from FCP so it exists.

 

[JayN54Sosa]

Either EKP or the actual LP sensor/line.

It's not completely flat like I first thought now that I see the chart on a screen, but damn close you only have like 2psi variance and it's at 30psi which is 20-30psi past failure.

datazap.me | Jayn54Sosa | New ekpm3 still psi drops in lpfp

datazap.me

New log with another EKPM3 off a different car and I also coded it.I also made a new post updating everything if you feel like checking it out.

 

[ShocknAwe]

A lot better. Still not good.

Have you checked your bucket to make sure the return lines are properly sitting inside? Or not kinked.

 

[NoGuru]

Yeah, still terrible, I would not rev out that car until you fix it. I agree with ShocknAwe, look for a kink or hole in the line inside the tank.