Juddering under light acceleration 325i (cured)

[Hayden0]

i have cured the juddering under light acceleration on my 325i and i have seen many posts and never a solution so i hope my solution works for others.

First of all i replaced all the service items plus the distributor cap and rotor arm also the blue temp sensor this made no difference.

After lots of messing about the final thing i did was take the cap off the airflow meter and i adjusted the mechanism just a slight bit to the right which richened the air to fuel mixture. its stopped the juddering and also when on choke in a morning it just drives as if its hot. Theres more power at bottom end and it pulls even harded at top end.

i hope this helps others because i know how frustrating it can be when your in traffic

[TPS]

I'm assuming you mean the Mixture Screw, Don't touch that!Thats an absolute no no. I had a 325 which juddered, turned out to be the Injectors needed cleaning.

[Barx325i]

that's akin to trepanning a headache.

not my area, but hope you made a mark where the screw was

[Hayden0]

the screw wouldnt bring the readings up into the manufactures setting so i had to go into the airfow meter itself. this was all done connected to a gas meter. im a mechanic myself so i have access to all the equipment

[Brianmoooore]

You would have been better off fixing the real fault (injectors been rebuilt?).
If and when the real problem gets sorted, you will still have problems because of the adjustments you have made

[Billwill]

It is possible that a previous owner adjusted the spring in one direction and you have now corrected it.

[Brianmoooore]

It is possible that a previous owner adjusted the spring in one direction and you have now corrected it.

Possible, but highly unlikely.
This part throttle, low revs juddering is caused by a weak mixture, and can have many causes. The engine is designed by BMW to run on the weak side under these conditions, and anything that makes the mixture weaker still will cause poor combustion and the running problem under discussion.
There's usually no one cause of the weak mixture, but once air leaks have been addressed and the injectors rebuilt, to bring their flow rate to back what it was when new, the problem usually goes away.
The bonus is that the engine will also run better at all other points in the revs/load range, giving improvements where you didn't even know you had a problem, even if you don't notice the improvements.