rought idle bad fuel consumption

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sam325is
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Wed Feb 13, 2008 7:17 pm

Hi everyone i have noticed when im at trafic lights that my idle although stable on the revometer is very lumpy.

i have also got very poor fuel consumption.

blue sensor is new so that eliminates that. im thinking air/fuel mixture is wrong as my emmisions are very good.

i have replaced pretty much everything with new parts from BMW so im starting to think it must be setting related.

Any ideas chaps?

Thanks

Sam
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Wed Feb 13, 2008 8:41 pm

have you done the spray test with some WD40 around the inlet manifold where it bolts to the head?
pete27577
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Wed Feb 13, 2008 9:36 pm

wot is this test???????????????
sam325is
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Thu Feb 14, 2008 11:33 am

no iahvent done it. i onkly had a new gasket on there 3,000 miles ago and it was well fitted so i doubt it would be that.

Does anyone know anything about the screw on the afm and fuel air mixture?
sam325is
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Fri Feb 15, 2008 11:16 am

bump
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Peter325iSE
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Fri Feb 15, 2008 11:35 am

Sam,

I have a similar thing going on with my 325i auto.

With the gearbox in N the idle is fine but if I drop it into D the idle begins to fluctuate. It's only very slight but annoying nethertheless.

When I bought the car the fuel tank was near empty and I had to drive over 10 miles in heavy traffic to the nearest petrol station. It's possible that I've picked up some crap and the fuel filter needs changing. Have you done this?

I remember years ago, a friend had a rough idling and very thirsty 520i auto, which suddenly got better when a new fuel filter was fitted.

I'm going to keep an eye on this post. Good luck with yours.

Peter
sam325is
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Fri Feb 15, 2008 11:48 am

yep i have a new fuel filter. fitted 3,000 miles ago. the idle needle is dead still. its just the vibrations in the car that are VERY ANNOYING they can be quite heavy at times.

it doesnt matter if its in neutral or not for me :cry: i think i might give ant a buzz and see if he fancy's having my car for a bit just to get that smooth running on the go.

i think it must just be a case of a few setting needing tweaking. but stiil keep the suggestions coming people. still think it could be afm screw.

what is most irritating is that i have replaced almost everything on this car, and it is all fitted properly.

Thanks

Sam
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