Poor idling 316 1800cc

[Dan!]

Hi guys, I bought an 81 316 a month or so ago and it has an idling issue which is more obvious when cold.

From cold it will fire immediately but after the first few revolutions will start to jump about erratically, cutting out if you dont keep the revs up with the throttle. You can't drive it until its warm as it cuts out so easily as soon as you are off the throttle. Once warm it idles reasonably but will still cough or miss every few seconds.

Im also aware that its running rich, it always smells of petrol even when hot. Seems to drive okay in general but I can't say for sure if its how it should be as iv never driven another one!

So far I have removed part of the auto choke, and found that the 'starter set lid' (number 15 in the below link) and found the contacts inside had totally fallen off.

http://www.realoem.com/bmw/showparts.do ... g=05&hl=41

I'm not sure where to get a replacement part for that? But I'm also unconvinced that is solely the problem. I have chanced the dizzy/rotor, plugs, leads, filters, tried 99ron and its still the same.

Any help is much appreciated, thanks in advance!

Dan.

[e21-Mark]

Treat yourself to a Weber. Better mpg, more power and smoother running.

[Jeroen]

Not sure if you immediately should replace a carb, especially this model that's not known to have many issues. With some parts from the breakers (auto choke bi-metal), clean jets, a check on vacuum leaks especially from the base gasket and a decent readjustment it might run smooth again. WN also sell an overhaul kit for the 2B4 carb: http://www.wallothnesch.com/vergaser-ei ... 13-03.html

[Peter V.]

I understand the reason why you all want to convert to weber but i feel a little bit sad that there are only a few people that would like to keep the old system of carburator on the car.

When you do a proper rebuild of the original carb it mostly runs perfect and you keep the origine of the car.

Do not get me wrong, everyone must do with his car what he/she wants offcourse.

[Dan!]

Thanks for the replies gents.

I wonder if the Weber route would do well for me, it seems the most appealing so far. Do you have a link or any info on buying one and which type to buy? Im fairly mechanically minded but I have never worked with carburetors before, all help is greatly appreciated.

Thanks, Dan.

[e21-Mark]

Each to their own but I hate Solex carbs. There's just too much to go wrong and a Weber is a much simpler, more efficient design. If originality is a concern though, stick to the original.

http://www.ebay.co.uk/itm/WEBER-32-34-D ... 2ec894ff95

Shop around or search for a used one.

[polov8]

Originality is a wonderful thing, but these cars aren't exactly valuable, they're more of a drivers car, and being able to drive it reliably is alot better than knowing your carb is OEM! Drop kick the solex and fit a weber, you won't look back.

[Reck]

The carb most go for is a Weber 32/34 DMTL. See my write up for tuning here...

http://bmwe21.net/forum/viewtopic.php?f=61&t=20640