[GodZhu]

Hi there everyone,

Hope everyone is doing well during these times. Just wanted to ask everyone for their input as I'm currently trying to solve an issue with my 2014 335i.

Some background information, it's a FBO 335i that was running a custom Gintani tune.

Was running absolutely flawlessly up until 2-3 months ago where I died in the middle of the highway with a Fuel supply fault, and then followed by a Drivetrain malfunction warning and the car stutters and dies and gets put into N gear.

Read the code and it was an intermittent HPFP code. Figured that it was the issue so I replaced it with an OEM one (These are expensive holy). Ran it for about 3 hours before I got the error again, and it died.

Another thing to mention is that I have a Stage 2 LPFP from Fuel-it!. But I have doubts that the LPFP could be the issue.

Something that I have noticed personally is that it happens when the tank is right under half, and that it doesn't happen when it's full. I've tried to read the code the first time but nothing came up, which was weird.

Car pulls hard when needed, tried to switch the maps to see if that was the issue but it still persists.

A wonder that I have currently is that, is the car thinking the tank is empty and just cutting the power out?

I would love for some input as I'm quite lost.

Thanks guys!

[thejeremyman9]

Well, given that the issue seems to be related to the fuel level and low pressure supply, i would immediately be suspicious of the LPFP... who installed it? Does it happen every time the tank gets under half, or it just never happens when its above that level? Could be an issue with the LPFP pickup, not the LPFP itself.

LPFP is not really needed unless you are going to run PI, so was there a reason you installed it in the first place? How is your EKP?

[GodZhu]

Originally Posted by thejeremyman9

Well, given that the issue seems to be related to the fuel level and low pressure supply, i would immediately be suspicious of the LPFP... who installed it? Does it happen every time the tank gets under half, or it just never happens when its above that level? Could be an issue with the LPFP pickup, not the LPFP itself.

LPFP is not really needed unless you are going to run PI, so was there a reason you installed it in the first place? How is your EKP?

I had a shop here install it, worked flawlessly during my time. The car has about 84,000Km on it and I installed it when it was at about 50,000Km. Thanks for clarification. Thinking about it now after, I might also suspect that it's the pickup. Pump itself is highly durable from what I've been told and such, so I don't think that there should be any issue with the LPFP itself.

EKP is normal. Everything runs normally other than that.

Do you think I could swap out the pickup from the OEM pump into the Stage-2 Pump?

I had plans to run PI this summer but given the whole situation right now, it seems far off into the distance.

[thejeremyman9]

Originally Posted by GodZhu

I had a shop here install it, worked flawlessly during my time. The car has about 84,000Km on it and I installed it when it was at about 50,000Km. Thanks for clarification. Thinking about it now after, I might also suspect that it's the pickup. Pump itself is highly durable from what I've been told and such, so I don't think that there should be any issue with the LPFP itself.

EKP is normal. Everything runs normally other than that.

Do you think I could swap out the pickup from the OEM pump into the Stage-2 Pump?

I had plans to run PI this summer but given the whole situation right now, it seems far off into the distance.

Not familiar enough with the LPFP in these cars to say... but maybe ask the shop that installed it how the pickup was. I imagine it should have been the same as the OEM. Maybe the pickup somehow fell off or is loose so its sucking air instead of drawing through the bottom of the pickup? I don't think its that much labor to just check out the LPFP, so that would be my next step.

[GodZhu]

Originally Posted by thejeremyman9

Not familiar enough with the LPFP in these cars to say... but maybe ask the shop that installed it how the pickup was. I imagine it should have been the same as the OEM. Maybe the pickup somehow fell off or is loose so its sucking air instead of drawing through the bottom of the pickup? I don't think its that much labor to just check out the LPFP, so that would be my next step.

Thank you for input, I've contacted them and I'll be scheduled to have it taken a look at it on Monday. I'll keep it updated to see what is wrong with it.

But from what the current outlook is like, it's the pickup as well.

[Smerke]

were you able to figure out the issue, i also have fuel it stage 2 lpfp and have been having this fuel supply issue, started out turning the car off when i was driving. Then the car will turn on for 10 mins till it turns off again. tried swapping a oem used lpfp, and ekp and that didnt fix it any ideas ?

[voxumf30]

This sounds very similar to what I've been experiencing on my car with stock fueling. Above half tank no issues with similar conditions, under and there's a high chance it'll happen under load. Most recently was driving through Georgia on a steep incline a few ticks above quarter tank on cruise control + comfort mode (80 mph), it threw a drivetrain error and required a restart that cleared everything up and was fine until I found a gas station. I made sure to keep that tank above a half the rest of my drive. Another thing I've noticed is once the gas light comes on, my miles left drops very fast. So that got me thinking it could be sensor related, but idk been dealing with this for 3 years lol.

The codes it throws is
110001 - Cylinder injection cutout. Pressure too low in high-pressure fuel system.
11A002 - High pressure fuel, plausibility. Pressure too low.

I'm running MHD stage 1 with FMIC currently, but it happens while stock as well.

[DJSF3014]

Originally Posted by voxumf30

This sounds very similar to what I've been experiencing on my car with stock fueling. Above half tank no issues with similar conditions, under and there's a high chance it'll happen under load. Most recently was driving through Georgia on a steep incline a few ticks above quarter tank on cruise control + comfort mode (80 mph), it threw a drivetrain error and required a restart that cleared everything up and was fine until I found a gas station. I made sure to keep that tank above a half the rest of my drive. Another thing I've noticed is once the gas light comes on, my miles left drops very fast. So that got me thinking it could be sensor related, but idk been dealing with this for 3 years lol.

The codes it throws is
110001 - Cylinder injection cutout. Pressure too low in high-pressure fuel system.
11A002 - High pressure fuel, plausibility. Pressure too low.

I'm running MHD stage 1 with FMIC currently, but it happens while stock as well.

Those codes are for the hpfp I've had many go out and every time once I put a new one it works perfect.

[voxumf30]

Originally Posted by DJSF3014

Those codes are for the hpfp I've had many go out and every time once I put a new one it works perfect.

Replaced a bunch on your own vehicle? I'd say that isn't the issue if you're constantly replacing HPFPs. Just playing devils advocate here, but how would the symptoms correlate to a half empty fuel tank? I wouldn't imagine the HPFP getting less fuel because the tank is half empty.

I also have no signs of the other typical HPFP issues such as rough idle, poor acceleration, or long cranks.

[thejeremyman9]

Originally Posted by voxumf30

This sounds very similar to what I've been experiencing on my car with stock fueling. Above half tank no issues with similar conditions, under and there's a high chance it'll happen under load. Most recently was driving through Georgia on a steep incline a few ticks above quarter tank on cruise control + comfort mode (80 mph), it threw a drivetrain error and required a restart that cleared everything up and was fine until I found a gas station. I made sure to keep that tank above a half the rest of my drive. Another thing I've noticed is once the gas light comes on, my miles left drops very fast. So that got me thinking it could be sensor related, but idk been dealing with this for 3 years lol.

The codes it throws is
110001 - Cylinder injection cutout. Pressure too low in high-pressure fuel system.
11A002 - High pressure fuel, plausibility. Pressure too low.

I'm running MHD stage 1 with FMIC currently, but it happens while stock as well.

Does your fuel level reading correlate with how far you have actually driven? Basically, it should be clear if your fuel level sensor is off such that the gauge is reading incorrectly relative to how much fuel is actually in the tank. It's possible you also have an issue with the pickup if the LPFP and EKP are fine.

I do agree those does are not necessarily HPFP. As far as i know, there is no LPFP pressure sensor so a fuel supply issue to the HPFP can cause those HPFP codes.

[DJSF3014]

Originally Posted by voxumf30

Replaced a bunch on your own vehicle? I'd say that isn't the issue if you're constantly replacing HPFPs. Just playing devils advocate here, but how would the symptoms correlate to a half empty fuel tank? I wouldn't imagine the HPFP getting less fuel because the tank is half empty.

I also have no signs of the other typical HPFP issues such as rough idle, poor acceleration, or long cranks.

They are aftermarket and yes I've replaced 4 but true I'm just telling you when I had those codes it was the hpfp. But I didn't have long cranks either when you start the car below half a tank does it start then after 10-15 seconds throw the rpms higher and throw those codes?

[voxumf30]

Originally Posted by DJSF3014

They are aftermarket and yes I've replaced 4 but true I'm just telling you when I had those codes it was the hpfp. But I didn't have long cranks either when you start the car below half a tank does it start then after 10-15 seconds throw the rpms higher and throw those codes?

Nope, under half tank it starts and idles normally. I originally thought it was due to high load conditions, being the first and only other times I noticed it happening was at WOT and going over 100mph.

Until my last trip, it happened at 2300 rpm around 80mph, but with a pretty steep incline.

[voxumf30]

Originally Posted by thejeremyman9

Does your fuel level reading correlate with how far you have actually driven? Basically, it should be clear if your fuel level sensor is off such that the gauge is reading incorrectly relative to how much fuel is actually in the tank. It's possible you also have an issue with the pickup if the LPFP and EKP are fine.

I do agree those does are not necessarily HPFP. As far as i know, there is no LPFP pressure sensor so a fuel supply issue to the HPFP can cause those HPFP codes.

Would it be weird to say I've noticed both? The times I think its off is when the fuel light comes on and gives me the 50mile warning. Consumption would drop by 5:1 (5 miles for every 1 actual mile) and it fluctuates quite a bit. I'd say its pretty spot on though when its above that half mark.

[thejeremyman9]

Originally Posted by voxumf30

Nope, under half tank it starts and idles normally. I originally thought it was due to high load conditions, being the first and only other times I noticed it happening was at WOT and going over 100mph.

Until my last trip, it happened at 2300 rpm around 80mph, but with a pretty steep incline.

It sounds like you are running out of gas then... Have you tested the fuel level sensor? There's probably a fairly easy way to bench test it.

[voxumf30]

Originally Posted by thejeremyman9

It sounds like you are running out of gas then... Have you tested the fuel level sensor? There's probably a fairly easy way to bench test it.

I have not, but will look around for how to do that and report back.

[zinner]

fill up your tank with gas and see how much it takes. If the sensor says 1/2 a tank it should take 7-8 gallons, if it takes say 15, the fuel level sensor is wrong.

[thejeremyman9]

Originally Posted by zinner

fill up your tank with gas and see how much it takes. If the sensor says 1/2 a tank it should take 7-8 gallons, if it takes say 15, the fuel level sensor is wrong.

But i think the issue might be his reads OK until half a tank. So that method could work, but a bench test of the actual sensor would be more accurate for diagnosing.

[voxumf30]

I came across this video

that shows how to test the fuel level sending units. My left tank was reading @ 170 Ohms and my right @251 Ohms. Not sure if this actually means anything since I can't find any information on them or find them in the technical training manual.

https://www.bimmerpost.com/goodiesfo...owertrain1.pdf

[Smerke]

I replaced my lpfp with a used oem one and put the original ekp back and my car started and ran good now im sending my stage 2 fuel-it walboro 525 back to fuel it to get a walboro 450 to pull less amperage

[voxumf30]

Originally Posted by Smerke

I replaced my lpfp with a used oem one and put the original ekp back and my car started and ran good now im sending my stage 2 fuel-it walboro 525 back to fuel it to get a walboro 450 to pull less amperage

Just to confirm you're saying things are running fine even with low fuel?