E87 118D 4B90 Error

Discussion in '1 Series' started by Liam Compton, Oct 28, 2019.

  1. Liam Compton
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    Liam Compton

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    So I went on a long journey (150 mile round trip) in my 1 series on friday. Got home and all was well, no issues , no lights etc.

    Got back in the car an hour later, picked up my friend, went over a bump and the engine light came on, I was limited to 2500rpm.

    I left the car, went back to it the next day and it drove fine for 10/20 minutes, no lights etc

    I didnt drive the car again until I went on a very short journey yesterday, the car cut out and has not started again since. A friend has plugged it in and I get the 4b90 code. Now I know this code can be a manner of all items but where do I start?

    I have ordered a low pressure fuel pump and a fuel filter and they arrive tomorrow, can I do anything else until I get these changed? Also is there a fuel pump relay or module on the E87?

    All help is appreciated.

    Just to add - we took the plastic cover off to expose the rail and injectors and it was all dry.
     
  2. bishbosh
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    bishbosh WARLORD Site Supporter

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    Welcome to the forum, (y)

    I've not experienced this issue myself, but reading around it sounds like it could be the low pressure fuel pump. If you have access to ISTA+ you could run diagnostics to check the function of the pump.
    I've seen people recommending to flush the fuel system to ensure it's clean and to prevent any metal particles that might be present causing damage to the high pressure fuel pump (HPFP) and injectors.
     
  3. Liam Compton
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    Liam Compton

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    Ive actually ordered the Low pressure fuel pump and also a filter to be changed today/tomorrow hopefully depending when they come. Just to add, when I lock and unlock my car whilst down by the glove box, I hear a noise like something spinning really fast for a brief second?
     
  4. Liam Compton
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    Liam Compton

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    Just to add, we changed the fuel filter, reset the diag and the car idled fine stationary for a good 10-15 minutes, we were revving it to 3000rpm and there was no problems at all.

    I drove a mile down the road and the light came back on, since then its been to a "small garage" and they said it may be injectors.

    I'm thinking it may actually be the fuel rail sensor itself? If the car ran perfectly when the code was cleared surely that leads us away from Fuel?
     

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