i just bought my first bimmer...a 1981 320i. its bone stock right now and i am thinking about some mods but.....it idles really rough when i start it cold and needs to warm up for at least 5, but more like 10 minutes before i can even drive it. i discovered a leaking fuel line between the fuel pump and filter which i repaired, but this did not solve the problem. when i do start it, the rpm's fall to about 500, it almost stalls, then it revs to almost 2 grand 2-3 times before settling into a rought idle at about 1100. any similar experiences/ideas? this is not only my first bmw but my first non-american car, so any input would be appreciated.

p.s...torque between 1k-2.5k SUCKS...any easy improvements i could make?

Hey welcome, might be the air auxilary valve. You got about 100tq, not much you can do with bolt ons. Might want to look into the ignition system from www.e21parts.net. Use the search function, there are many questions that you might have, that have been covered over and over agian.

I think everyone has the cold start problem. I don't think its a problem, much less just an old motor that doesn't fire up perfectly during the cold... You could try taking off your cold start valve and putting it into a cup, start the car, if it blows a fine mist then its good... But since you don't know Non-American cars much less BMWs. Do what I did, get a Haynes manual... Its worth it.

As CJ stated, make sure your aux air valve is opening. Its mounted in the center of the head next to the valve cover and has a black plug.

Your car has k-jet, or cis (constant injection system) fuel injection, which uses hydraulic pressure and flow to precisely meter the correct amount of fuel for a given air flow. One of main components in the system, called the warm up regulator, adjusts fuel pressure (and thus mixture) based on the temperature of the motor. It is basically a valve that bleeds off excess fuel to control fuel pressure as needed. I could go into a lot more detail if you need, but basically there is "cold" control pressure and "warm" control pressure. It sounds like your cold control pressure is too high, which causes a lean running condition. You can try removing the warm up regulator (WUR) disassembling it and cleaning it to see if the condition improves. It is located under the starter motor. If not, it is possible to tune the cold and warm control pressure independantly (I have done this and have info on how to do it if you want), but most just replace the WUR.