E53 startup problems

[Lozzz]

Hi I'm new to this forum, but have used information off here many times and. Come across some sound advice.

Basically I have an e53 x5, a couple of months ago I went to start it as usual but it took slightly longer to fire up, it was a hot day and it was the first time I started it that day, didn't think much of it until a few weeks later when it did it again,
the starter carries on spinning until I give it a rev to get it going. It has got more and more frequent, mostly the first time I start it in the day when the engine is cold but sometimes if I leave it a few hours.
Now it can take 5 plus seconds of cranking to get it started even pressing the gas doesn't do much. It is only intermittent and I can put my finger on why and when it will do it e.g ambient temperature etc apart from when the car has been sat for a few hours.
I've tried sitting in for a few seconds with the ignition on to let the fuel pump prime but it's still the same, so no leaky injectors.

Any help appreciated

[Ironman]

I swapped te engine for 01 bmw x5 3.0 but im not sure why i cant crank it up any help

[upallnight]

Did yopu also swap out all the electronic? EWS comes to mind.

[Lozzz]

Would it still throw up codes even though the engine light isn't on, I have ordered a scanner today so should be here in a couple of days

[Ironman]

Originally Posted by upallnight

Did yopu also swap out all the electronic? EWS comes to mind.

Nope as far as i know and i called the dealer parts department they said everything matches but im thinking about the flywheel bc the used new engine was 5 speed so we had it removed the old flywheel and set it back in the new engine but the mechanic was not sure about the position so i dont know if it make any sense that the timing its firing incorrectly bc of it....

[upallnight]

To the OP, sounds like a bad fuel pump if it is intermittent. And No, a bad fuel pump will not throw up a code. Connect a fuel pressure gauge at the fuel rail and see what kind of fuel pressure is in the rail with just the key in the on position, now start the engine up and see what kind of fuel pressure you have when the engine is running. It would be great if you could perform this test when the engine doesn't want to start.

[Lozzz]

Should the fuel pump come on when u turn the ignition to 2? I only hear a loud buzzing that sounds like the fuel pump trying extra hard when the engine has just fired up. And it's deff not the air sus pump

[upallnight]

The fuel pump comes on initially when the key is turn to the run position and then to the start position but turn off until the engine actually starts. That is why I ask you to do a key on with the engine not starting and look at the fuel pressure gauge and then a engine running and a look at the fuel pressure gauge.

[Ironman]

Actually the fuel pressure it's good , it's showing p0604 but I'm still thinking about the flex plate anyone has a diagram or pic that shows how to set the flex plate up