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Hi,
I have only driven my 1981 316 for a little while now and am surprised at the poor fuel consumption I am getting - 13 litres per 100 km. I never expected it to be great but that is much worse than I expected !

I think (hope) that the engine itself is in very good shape - genuine 106,000 km (one previous owner) with BMW service book. The car was last serviced by an independent mechanic 1,000 km ago. The engine doesn't smoke and sounds very sweet when warmed up idling. The car is completely standard.

While taking it out of the driveway today I noticed that the idle was running very high (there is no rev counter but it sounded as if the automatic choke was fully on). I revved it once and it settled down. I then noticed intermittently similar high revs (as if the choke was fully on) when idling after the car was warmed up. Again it then calmed down.

I have read that the carbs on these cars are a problem ( http://www.fritzsbits.co.uk/services/bm ... 30-m20-m10). Based on the above do you guys think I should replace it? If so with what?

I hear that Webcon produce a direct Weber replacement kit for around £400. Or should I go with another carb set-up (side draft on Lynx inlet manifold)? Or better to convert to fuel injection?

Appreciate any comments.

Thanks in advance

Why not replace the entire engine? Seriously: why replace? Find a local carb specialist and give it an overhaul. Especially on the 1.8's with the 2B4 carb its good and gives enough juice for good performance, and yes after some TLC it should defo give you better mileage.

I spoke to a friend of mine who is really into his old Alfas who volunteered to have a look at it. A good spray of carb cleaner and it seems to be running better. The automatic choke is still a little sticky though when cold (by giving it a little rev this seems to sort things out) but overall a big improvement !

I have a similar problem with my Pierburg 2B4. I would dearly love to keep it original but two carburettor specialists I have spoken to will not service it at all. It is possible to get it overhauled but it means being off the car for at least 3 weeks. I do some work on the car myself but removing and installing carbs is not my forte. It’s hard to decide what to do, especially as replacing it with a manual choke carb it would mean drilling my ‘perfect’ dashboard trim ( I think).