[Tawz123]

Originally Posted by dpaul

Not sure I understand this statement.

Are you saying that your fuel rail pressure is low but when you disconnect the injector, the pressure increases?

What are the pressure values with injectors connected and disconnected?

EDIT: I looked at your previous thread. Sound like your injectors were very leaky, apparently as common a problem with the N43 as the N54. Have you replaced them?

Yeah I think there leaking I haven't replaced them I pulled them out
And cleaned them up. But there on back order no one can get them

[dpaul]

Originally Posted by Tawz123

Yeah I think there leaking I haven't replaced them I pulled them out
And cleaned them up. But there on back order no one can get them

Unfortunately, there is no 'cleaning' and there is no 'rebuilding' for these high pressure injectors. What a clown show BMW put on with these things!

I think that N54 injectors, which are expensive (13538616079 $350-600@) but readily available, will work with the N43 and N53 engines, even though the part number is different. Keep in mind you need to recode (INPA can do this) for the new injector flow rates.

I am 100% sure I've read of folks doing this but have not seen the vehicles in question so do your due diligence.

[Tawz123]

Originally Posted by dpaul

Unfortunately, there is no 'cleaning' and there is no 'rebuilding' for these high pressure injectors. What a clown show BMW put on with these things!

I think that N54 injectors, which are expensive (13538616079 $350-600@) but readily available, will work with the N43 and N53 engines, even though the part number is different. Keep in mind you need to recode (INPA can do this) for the new injector flow rates.

I am 100% sure I've read of folks doing this but have not seen the vehicles in question so do your due diligence.

Oh okay thanks bro I didn't know they were available, Ye i have inpa and ista so I can
recode them. Because if u think about if the timing was off I would have timing codes right?

[dpaul]

Originally Posted by Tawz123

Oh okay thanks bro I didn't know they were available, Ye i have inpa and ista so I can
recode them. Because if u think about if the timing was off I would have timing codes right?

Yes, I'd guess you'd see codes associated with cam mistiming if you chain was stretched or guides broken (assuming you are referring to the famous N43 timing chain stretch-break-plastic guide pieces plugging the oil pump issues). But I but have no personal experience with the N43. It's a bit of a nightmare it seems.

I guess I'd throw in one more suggestion; that you change the oil before you start the engine with the new injectors (if you decide to go that route). There's probably a ton of gasoline in the oil by this point - that will kill the bearings quick. At least it will in an N54!

[Tawz123]

Originally Posted by dpaul

Yes, I'd guess you'd see codes associated with cam mistiming if you chain was stretched or guides broken (assuming you are referring to the famous N43 timing chain stretch-break-plastic guide pieces plugging the oil pump issues). But I but have no personal experience with the N43. It's a bit of a nightmare it seems.

I guess I'd throw in one more suggestion; that you change the oil before you start the engine with the new injectors (if you decide to go that route). There's probably a ton of gasoline in the oil by this point - that will kill the bearings quick. At least it will in an N54!

Yes dpaul your right about that absolute nightmare. I'll copy over that part number to see the availability. But yes I did change the chain and guides due to a stretched chain too much slack and very noisy on first start up.

[beardman]

Hey Dpaul, it's been a minute but I finally got into the tests you suggested earlier in INPA.
Before I cleared everything, there was an error stored on these modules:
CAS, A10A
KOMBI, A559
EGS, CF 07
DME/DDE, 2F6C, 2AAF, CD87, 2FBE

After I cleared, everything just read "OKAY".

Then it got interesting. The car was acting like it was really flooded. I held the accelerator pedal to the floor and tried cranking. Maybe 10-12 seconds of cranking and it fired up. It sat there and ran like crap but then in a minute or so it cleared up. It was then running and idling perfect. I could rev and no problem. It was in limp mode according to my screen though. I let it run for 10-15 minutes then I shut it off, and would not restart.

When I go to start the car I do not hear the electric fuel pump turning on. After pulling the codes again, all the modules are reading "OKAY" and the DME/DDE is reading 2F6C, 2AAF, and 29F1.

I feel like it was a really good sign that the car fired up and ran, but I still am not sure if I actually got anywhere at all.

Thanks again for any help.

[dpaul]

Originally Posted by beardman

Hey Dpaul, it's been a minute but I finally got into the tests you suggested earlier in INPA.
Before I cleared everything, there was an error stored on these modules:
CAS, A10A
KOMBI, A559
EGS, CF 07
DME/DDE, 2F6C, 2AAF, CD87, 2FBE

After I cleared, everything just read "OKAY".

Then it got interesting. The car was acting like it was really flooded. I held the accelerator pedal to the floor and tried cranking. Maybe 10-12 seconds of cranking and it fired up. It sat there and ran like crap but then in a minute or so it cleared up. It was then running and idling perfect. I could rev and no problem. It was in limp mode according to my screen though. I let it run for 10-15 minutes then I shut it off, and would not restart.

When I go to start the car I do not hear the electric fuel pump turning on. After pulling the codes again, all the modules are reading "OKAY" and the DME/DDE is reading 2F6C, 2AAF, and 29F1.

I feel like it was a really good sign that the car fired up and ran, but I still am not sure if I actually got anywhere at all.

Thanks again for any help.

First, do not hold the accelerator down while you are trying to start. It's not a 327 Chevy. There's no carburetor. Do not do that.

29F1 is fuel pressure plausibility i.e. the DME is detecting fuel pressure readings that are out of the normal range.

There are many possible explanations; the EKP, the LPFP, the LP pressure sensor, the HPFP, the rail pressure sensor, even battery voltage fluctuations. I'm sure there are more possibilites.

Since this appears to be an intermittant problem, you can probably rule out any coding, programming or variant incompatibility. That leaves the hardware (pumps) and the electrical (sensors, wires, connectors).

to begin with, lets see if your LPFP can be properly controlled. STRONGLY ADVISE PUTTING POWER SUPPLY ON CAR OR AT LEAST A DECENT BATTERY CHARGER.

Test 1:
INPA->E90->engine->N54-> F6 (component trigger)-> F1 (Actuator 1)-> F5 (Electric fuel pump)->F1 (ON).

That should turn on your fuel pump and the bar graph should indicate about 100%. Let it run 10 sec or so, take a screen shot, then hit F2 (OFF)

If you pass test 1 go on to test 2:

Test 2:
Back (F10) -> F1 (Actuator 1)-> F5 -> F1 (ON). Then very quickly hit back then back again -> F2 (Actuator 2)-> F6 (fuel control valve)

You should see about 5000 on the bar graph - this is the pressure in the low pressure line. Screen shot, post

[beardman]

Thanks Dpaul I ran that test, first test passed, pump would turn on. For the second test I'm not 100% sure what it is telling me but it being "in the red" on the graph maybe points to something? Screen pic attached.

Sorry I didn't mean to make you think I was feathering the accelerator to get the car to start, I have worked on lots of fuel injected cars that enter a "clear flood" type mode when you pin the accelerator to the floor while you crank, it cuts the fuel. But, I will admit, I had no clue if that was the case on our cars, now that I know it is not, I will not do that anymore.

[dpaul]

Originally Posted by beardman

Thanks Dpaul I ran that test, first test passed, pump would turn on. For the second test I'm not 100% sure what it is telling me but it being "in the red" on the graph maybe points to something? Screen pic attached.

Sorry I didn't mean to make you think I was feathering the accelerator to get the car to start, I have worked on lots of fuel injected cars that enter a "clear flood" type mode when you pin the accelerator to the floor while you crank, it cuts the fuel. But, I will admit, I had no clue if that was the case on our cars, now that I know it is not, I will not do that anymore.

Just to be clear, for TEST 1 just the fuel pump turning on is not "passing". You must see a number close to 100%. That's why I asked to you take a screen shot.


Ok, assuming you saw close to 100%, then 13606 hPa in TEST 2 is a very odd pressure to read at the rail, equivalent to about 200 psi. That's way lower than you'd expect at idle (engine running) which should be about 750 psi - that's why it's in the red. However, this pressure is way higher than you'd expect with just the LPFP running (which is the case in your test I am assuming) i.e. about 70 psi or about 5000 hPa.

So, this could be the result of a faulty rail pressure sensor or, I suppose, a faulty fuel pressure regulator (under driver side read seat). If I remember correctly, you have already replaced the LPFP, the HPFP and both low and high pressure sensors. So assuming you used the correct parts and installed them correctly, that doesn't leave much. But 200psi from the LPFP is way too high.

[beardman]

Sorry, I should have mentioned that it read at 99.6% during test one.

Engine was not running with that, just LPFP.

Correct, I installed a new HPFP, LPFP, and both high and low pressure senders and a battery and there were no changes in the cars symptoms.

Looks like the fuel pressure regulator makes the most sense to check out next.

[beardman]

Well the new fuel pressure regulator assembly did not make a difference. The car just cranks, runs for about 1-3 seconds and dies. I did some reading and it seems like the fuel pressure reading I posted is kind of strange. I guess so far that's the most concrete clue I have right? Any thoughts on what could cause a fuel pressure reading of like 200lbs, or maybe just make the computer think the fuel pressure is that if it is not? new sender and old sender are both showing the same pressure in INPA so i don't think it is the sender unless both are bad.

[dpaul]

Originally Posted by beardman

Well the new fuel pressure regulator assembly did not make a difference. The car just cranks, runs for about 1-3 seconds and dies. I did some reading and it seems like the fuel pressure reading I posted is kind of strange. I guess so far that's the most concrete clue I have right? Any thoughts on what could cause a fuel pressure reading of like 200lbs, or maybe just make the computer think the fuel pressure is that if it is not? new sender and old sender are both showing the same pressure in INPA so i don't think it is the sender unless both are bad.

This certainly is consistent with a fuel delivery problem of some sort. At this point I'd want to
1) check the fuel pressure at the rail with a gauge, rather than rely on electronics.
2) make sure that the LFPF/EKP could actually deliver fuel at a reasonable volume.
3) verify integrity of the wires connecting the fuel pressure sensors to the DME. If you don't have access to ISTA or Newtis for wiring diagrams, provide the last 7 characters of your VIN and I can post them for you.

[beardman]

That would be great! Last 7 of vin are NH80600

[dpaul]

Ok, in order
HP sensor wiring diagram
LP sensor wiring diagram
HP sensor X6328 connector pinout
LP sensor X63280 connector pinout
DME connector X60007 pinout
DME connector X60005 pinout