Slght juddering!

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jmec
E30 Zone Newbie
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Joined: Sun Sep 23, 2012 11:00 pm
Location: Battle, East Sussex. UK

Sun May 24, 2015 6:03 pm

Help/advice please. Accel & decel are ok but I'm getting slight juddering on a light throttle in any gear. Idle is a tad lumpy. Fuel filter is pretty new, injectors have been cleaned & cal'd by zone trader. TPS clicks when it should.
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Marneus
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Sun May 24, 2015 6:24 pm

I'm having the same problem so will be interested in the answer too.
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Brianmoooore
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Joined: Mon Jan 10, 2005 11:00 pm

Sun May 24, 2015 7:29 pm

The light throttle map is fairly weak by design, and this tends to be symptom of the mixture being a little too weak. If the injectors are up to scratch, then the likely cause is one or more air leaks into the inlet tract after the air meter.
You haven't said what car you have, but a missing cap on the (unused in most cases) connection to the fuel vapour carbon cannister is a common cause.
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jmec
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Sun May 24, 2015 7:56 pm

Thank you Brian. No I didn't mention the model (what a numpty) 1990 325i cab. I've got a 200 mile motorway (traffic jam) run tomorrow but I'll try and sort it after.
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jmec
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Posts: 164
Joined: Sun Sep 23, 2012 11:00 pm
Location: Battle, East Sussex. UK

Sun May 31, 2015 4:53 pm

After removing the throttle body locating & the redundant offtake, that looked sound, I refitted it with sealant. The throttle body went back with a new gasket. I also replaced the original servo tube pipe clips with jubilee clips. I did order a rubber boot which came through with an extra offtake! That will be returned in the hope of getting the correct one. I may as well change it. However a test run today was encouraging! Trying to find a smooth traffic free road to hover on the throttle was the most difficult task; the nearest such road is probably in Holland! Bearing in mind what you said Brian, re the throttle map I'm a happy bunny at this point, thank you.
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