DIY E89 Z4 fuel system - DI only LPFP / HPFP

Krampus

Specialist
Aug 8, 2020
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Finland
I put aprox 10liters in after swap,do not know which side of tank it entered.Suguest to put in additional 10liters? Would be mess if need to pull the pump out again.
10l is enough. I put 5l after fuel pump change and it was ok.
 
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Neg89

Specialist
Jul 4, 2021
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So I have already 20 litres in my tank and it does not work now I am confused about this wiring I really don't want to pull out the pump can I reverse the wires in the entrance?
 

Neg89

Specialist
Jul 4, 2021
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It was a mess but I changed the wires internally.There was internal ground as i suspected,so changing wires at the plug was no go. The car started up just fine after priming but now I have EKP error 6292 Control voltage too low. I made voltage fix in protool even before startup.There is zillion parameters in ekp settings which i do not understand at all, i suspect that something need to be changed, any info on this? Help would be so nice.
 

Neg89

Specialist
Jul 4, 2021
67
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So.

Like i said before , the wires on the new pump needed to be reversed =opposite like was in pictures in this thread.

I had EKP error 6292 Control voltage too low right after startup.

After digging in the NCSEXPERT,DUMMY,INPA and protools i found that "throttle voltage fix" which i applyed straigt after pump swap was the problem .

After finding and partially understanding the hex codes in the ekpm3 module, i found out that the values was altered like the Vehicular diy made them manually in the posted youtube vid. But there is a one catch, THE E89 IS UNICORN. And the values from regular n54 from all other bmw does not apply to Z4. (THEY ARE DIFFERENT). After coding back to stock parameters the error finally go away.

After the loging i noticed that my HPFP pressure sill dips between certain RPM. Looks even worsy than my previous logs which was made before pump install and 5.000 km before.

The shitty thing is i can not see the LPFP pressure to confirm that the new pump works better than old one, it would be really good retrofit or to at least know the pressure somehow.

Please ta a look at my logs and comment.
The situation where i am now with swapped LPFP

The log 5.000km ago with oem pump.

1. Do it looks like the HPFP is weak and dying?
2. I see that after throttle release sometimes the Lambda for bank 2 is not going to 234 as much fast as bank1, i have changed the injectors in one bank 5.000 km ago and put the old ones which looked the best to another bank (but not remember which bank). Is it possible that leaky injectors cause HPFP pressure drop?
3. On the last ride i felt few times a jerk in power somewhere above 4,000rpm , that was very noticable but very short.
4. Do the presure regulator ond its filter may cause this (i left original ones in.)


I will be very thankful for help, new HPFP is not cheap as not injectors .
 

Krampus

Specialist
Aug 8, 2020
64
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Finland
1. Yes I agree.
2. Can you check your o2 sensor voltages with Ista or inpa?
3. HPFP pressure drops after 4000rpm and feels jerky because of that?
4. No information on the matter. I removed the hpfp filter from my car and replaced the lpfp with a new filter and added a filter to the fuel line.
 

Neg89

Specialist
Jul 4, 2021
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Hi.Do i need to compare voltages between B1 and B2?

I remembered that that few times after i put in tune which was given to me by tuner as temporary till i replace LPFP i reciewed
  • 29E1 (10721) - Fuel Mixture Control 2 (bank 2, cylinders 4-6).
After a while it doest popped up anymore.

Sometimes,realy rare i have 6cilinder misfire,pulle the flugs,Nr 6 is blacker ,all others super clean(unlike they were before injector change), the bank 2 have old index9 injectors.

Now i wonder do i change the injectors(i believe i need to change all3 insted of mixing) or simptoms sugguest that the the hpfp is still going bad and i will need it changed anyway.
 

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Krampus

Specialist
Aug 8, 2020
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0
Finland
The voltage must be approximately the same in both banks. Of course there is little variation in voltage. Before the catalyst just under 2 volts and after the catalyst about 0.7v-0.9v if I remember correctly. Live data you measure at idle. Inpa seems to show the limits to the acceptable voltage.
I had code 29E0 mixture control and the injector leaked in bank 1. Cylinder 1 had a black spark plug tip. Idle was bad and other error codes came as well. Replace all injectors in bank 2 with at least index 11.
 

Neg89

Specialist
Jul 4, 2021
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I will check voltage tomorrow. From my logs do it look that my car runs rich? While fitting in LPFP and exhaust was removed at least bank 1 downpipe was covered in sooot, did not look at other one.
 

Neg89

Specialist
Jul 4, 2021
67
6
0
Hi fellas.Happy new year.

I am thinking of adding Reflex+ and PI to my e89.

I am FBO tte500 turbos, 295 pump.

Car runs great but, i want that little extra (say 50Hp).

Tuner said with bigger hybrids like tte600 i will loose spool which i do not want to happen.


I assume that by adding Reflex+ and run it for PI control+flex fuel solution i can live without need of Pod (which i dont want to install).

Also if i understand correctly it is able to log LPFP in Reflex+, the parameter which we were unable to log onb/E89.


The info for Reflex is not so great. Please share your opinion.
 

sjobusen

Lurker
Aug 8, 2021
16
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0
Hi fellas.Happy new year.

I am thinking of adding Reflex+ and PI to my e89.

I am FBO tte500 turbos, 295 pump.

Car runs great but, i want that little extra (say 50Hp).

Tuner said with bigger hybrids like tte600 i will loose spool which i do not want to happen.


I assume that by adding Reflex+ and run it for PI control+flex fuel solution i can live without need of Pod (which i dont want to install).

Also if i understand correctly it is able to log LPFP in Reflex+, the parameter which we were unable to log onb/E89.


The info for Reflex is not so great. Please share your opinion.
Did you solve your hpfp dip in pressure?

I am at the same place. Can not get my hpfp to hold the pressure up on e45 mix fuel and 20 psi on my 17t turbos...
Car runs perfect, but when doing WOT my rail pressure drops bad... :(
 

Neg89

Specialist
Jul 4, 2021
67
6
0
Did you solve your hpfp dip in pressure?

I am at the same place. Can not get my hpfp to hold the pressure up on e45 mix fuel and 20 psi on my 17t turbos...
Car runs perfect, but when doing WOT my rail pressure drops bad... :(
Hello. I bought PFS POD get it shipped to europe but have not decided if i will install it or not. The issue is not an issue,the car just can not deliver enough fuel without overdrive or pi. If you from europe?
 

sjobusen

Lurker
Aug 8, 2021
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Hello. I bought PFS POD get it shipped to europe but have not decided if i will install it or not. The issue is not an issue,the car just can not deliver enough fuel without overdrive or pi. If you from europe?
Yes I live in Sweden. Why should not e89 will be able to output about 600hp crank when other n54 can do it... without PI or overdrive? :)
Seen many 335 that runs great with only upgraded lpfp and stock hpfp doing maybe over 600hp at crank....
 

Neg89

Specialist
Jul 4, 2021
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I installed new 535 walbro lpfp, new injectors,new bpm3, nothing changed.I am running straight 98fuel around 24PSI. Nothing of stated and changed did improve hpfp dip. So i bough pod.Do you have e89 or different car?
 

sjobusen

Lurker
Aug 8, 2021
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I installed new 535 walbro lpfp, new injectors,new bpm3, nothing changed.I am running straight 98fuel around 24PSI. Nothing of stated and changed did improve hpfp dip. So i bough pod.Do you have e89 or different car?
Ok. Did you change your HPFP to a new one? Yes I drive e89 ;)
Maybe my HPFP starting to get tired?
 

sjobusen

Lurker
Aug 8, 2021
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600whp with eMix. Stock pump not going to get there. ethanol requires up to 30% more volume, depending on level of mix.
Has anyone ever maxed out the stock LPFP on Z4? We do not have any lpfp sensor so many of us just speculate about the lpfp capacity of the z4.... just curious :)
 

Torgus

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Nov 6, 2016
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Has anyone ever maxed out the stock LPFP on Z4? We do not have any lpfp sensor so many of us just speculate about the lpfp capacity of the z4.... just curious :)

I don't think anyone wants to...it is risky to be on the ragged edge of your fueling. If you go super lean you can pop the motor. Throw a 535 in the bucket and a 2nd externally on a hobbs/relay would be my suggestion if the single 535 is not enough. Walbros are cheap all things considered.
 

sjobusen

Lurker
Aug 8, 2021
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I don't think anyone wants to...it is risky to be on the ragged edge of your fueling. If you go super lean you can pop the motor. Throw a 535 in the bucket and a 2nd externally on a hobbs/relay would be my suggestion if the single 535 is not enough. Walbros are cheap all things considered.
I already have one 535 pump in tank. But I want to know if anybody know how much stock LPFP in E89 I capable of :)