[KK0124]

Morning all,

Looking for some help please.

I have a 57 plate N47 (D20A) 320d touring. Timing chain failed so I replaced the engine.

Car starts and runs great, revs freely up to 4k etc. The problem is when its driven under load, its pulls well up to 3k revs then completely loses all power....almost stalls but doesnt quite then recovers to drive fine under 3k and does the same if i go beyond 3k revs.

Checked the live data and all looks normal except the fuel 'pre supply pressure' this drops significantly down to 1 bar when i hit 3k rpm. I compared the live data with my 120d and all parameters match except the pre supply pressure which drops to around 9 bar when i hit 3k rpm rather than the 1 bar.

Im thinking its either the pre supply and might replace the pump in the tank....or its a red herring and the pre supply dropping when i hit 3k rpm because the ECU is telling the car to go in to limp mode..

Any suggestions would be greatly appreciated.

Thanks in advance, Kris.

[Andy198712]

no codes at all?

[KK0124]

One fault code to do with glow plugs but I don't think that's associated with the problem I am having.

[ChawenHalo]

Turbo related?

[KK0124]

I thought it may be turbo related - over-boosting. But when it gets to 3k it loses all power, not just the boost.

Anyway the turbo and the actuator have both been replaced and didn't cure it

[KK0124]

I Still haven't managed to find a solution to the above problem.

When i replaced the engine i used the engine loom from the donor car (318d) and not my car (320d). The replacement engine has the exact same engine code but does anyone know if there is a variation in the loom that could be causing my problem?

[bishbosh]

Did you swap over your injectors from your old engine to the donor engine?

[KK0124]

BishBosh, thanks for the suggestion. Swapped injectors and turbo at time of engine replacement so they are both original to the car.

[bishbosh]

Ok, I think it's only the injectors that are different between the various engines.
I would go with your original suggestion and look at the fuel supply.

[KK0124]

Does anyone know if the injectors being in the wrong order (IE - originally cylinder 1 but now in cylinder 2) would cause the above problem?

[rasa bmw]

i doubt that would have anything to do with it.they are not numbered.and when you have a replacement injector it would have to be same number..i m sure it will be fuel pump related,,on another note..have you changed the fuel filter recently..been known to cause all sorts of probs..

[bishbosh]

Originally Posted by KK0124

Does anyone know if the injectors being in the wrong order (IE - originally cylinder 1 but now in cylinder 2) would cause the above problem?

Each injector has a code on in that the ECU needs to know about, I'm not sure of the correct terminology but this code is then used by the ECU to know precisely the amount of fuel to inject.

Having the injectors swapped round without updating the ECU means they won't be running as efficiently as possible.

[bishbosh]

Originally Posted by rasa bmw

i doubt that would have anything to do with it.they are not numbered.and when you have a replacement injector it would have to be same number..i m sure it will be fuel pump related,,on another note..have you changed the fuel filter recently..been known to cause all sorts of probs..

Unless the filter has been installed incorrectly I doubt it's that. The fuel system self-bleeds. When I changed my fuel filter, the engine cranked for about 15 seconds before starting but then it was fine.

[rasa bmw]

Originally Posted by bishbosh

Unless the filter has been installed incorrectly I doubt it's that. The fuel system self-bleeds. When I changed my fuel filter, the engine cranked for about 15 seconds before starting but then it was fine.

when replacing fuel filter.its best to fill it up with a bit of diesel,then when fitted,turn key in ignition without turning car over,this primes the fuel line using the fuel pumps,although on a push button start car i guess this is not possible...or is it?

[bishbosh]

Yes that's what you do, you just don't put the clutch pedal down, pushing the button will turn on the ignition but not start the motor. Sorry, I didn't make it clear in my earlier post.

[Len_Beach]

We have a 16 plate Mini Cooper SD with the N47. A couple of weeks ago this threw an error on the dash showing restricted performance, proceed to a dealer. This came up a few times and resulted in the car not being able to accelerate above 80mph. There were probably issues at lower speeds but the car didn't throw the issue until on the motorway.

BMW Assist came out and diagnosed a faulty EGR Valve which, once replaced cured the issue.

[rasa bmw]

maybe worth a good clean of the egr.easy and free fixes first

[KK0124]

thanks for all the suggestions, will try them and update you all

[KK0124]

Solved!!. Tried lots of different sensors, diagnostics, premium fuel, new turbo, egr etc. Plugged the car in to a new diagnostic system last week and did a standard 'erase all codes' and the problem is gone. Must have been a historic fault code that was throwing the car in to limp mode over 3k rpm

[nemz]

Just to add here, injectors can be coded to the car in the DDE service functions in ISTA. These N47 engined cars also have a fuel bleed service function which should be used whenever the high pressure side or fuel filter has been changed. Although they will self bleed eventually, this service function should be used rather than spinning the engine over till it starts to avoid potential high pressure pump damage.

[Casper1996]

I have the same problem.

what program did you use to reset the error codes

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