afm adjuster locked please help

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reaz12345
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Wed Oct 03, 2007 8:52 pm

hello peps ive got a 325i cab but the air flow adjuster seems to be totaly closed of. ive tried with force to turn the nut with a allen key but it wount turn. its closed of totaly so no air going into the engine as engine sounds like shit

any ideas??????????????
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march109
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Wed Oct 03, 2007 8:56 pm

I thought thse were factory set and shouldn't be fettled with at all anyway?
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reaz12345
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Wed Oct 03, 2007 9:01 pm

i dont know mate for same reason mine closed off
march109
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Wed Oct 03, 2007 9:04 pm

yeah it should be! its factory set, if the afm is at fault then take it off and check the movement inside.
325i Tech 1 Touring, breaking.

2.5 high comp. M20, 3.64 LSD, Fully undersealed, Spax springs & Bilstein shocks, s/s exhaust, Alpina rep wheels and more.
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reaz12345
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Wed Oct 03, 2007 9:09 pm

but a few machanics have looked at it and said the reson why its running ruff is becase it need to be air flow needs to be adjusted to 2 and a half anti clock wise.
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Wed Oct 03, 2007 9:12 pm

That screw only affects the air flow for idle........

It is set at the factory, and each AFM is different. The setting is stamped on the AFM.

It has no bearing on the running of the engine above idle.
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march109
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Wed Oct 03, 2007 9:20 pm

Did anyone actually check the mechanical operation of the AFM tho, adjusting the mixture won't help anything if all it needs is cleaning and lubricating. And you CANNOT correctly set the AFM withought knowing the exact CO2 readings, there is ABSOLUTLY NO WAY your mechanic/s can tell you it needs any ammount of turns this way or that since they have no idea withought adjusting it with live CO2 readings.

Find yourself another garage.

Idle control valve can only be cleaned out with, for example, brake cleaner (or replaced if stuck and knackered).

AFM CO allen key adjuster screw can only be effectively adjusted in conjunction with an exhaust probe measuring the burnt mixture coming out. If the screw had a cover on it all AFMs are calibrated at the factory each one is slighty different electrically.

Have a look by the screw that is used to adjust the air by-pass for the idle C02. On the casing, near the hole, you will see 3 numbers. These 3 numbers are a measurment, in mm, ie : 14.6. This measurement relates to how far down the screw must be for that AFM to be set correctly.

If everything else in your engine that account for the rough running was fine then the screw wouldn't even need touching.
325i Tech 1 Touring, breaking.

2.5 high comp. M20, 3.64 LSD, Fully undersealed, Spax springs & Bilstein shocks, s/s exhaust, Alpina rep wheels and more.
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