Poor starting problem bmw 318 ti

either you have a problem with the gearbox oil pump or the converter.

NEED TO CHECK IGNITION COILS WIRES HOOK UP.CHECK THE COIL WIRES ELECTRICAL CONNECTOR MAKE SURE IT HAS GOOD CONNECTION AND ALL COILS GETTING GROUND.

check your hoses see if when runnig they close up,if not loo for vents for letting are out of the system if ther is a air pocket inyour coolant system it willcause the engine to overheat make sure to run the heat when refilling coolant system. if this fails to solve your problem look for a gurgling sound coming from the rad or over flow tank look for this when engine is cold and runnig if you do hear this then you might have a blown head gasket.you can buy a blown headgasket detection kit from your local auto parts store if you do hear or see this symtom.

HAVE IT TESTED FOR TROUBLE CODES THAT IS THE KEY TO FIND THE PROBLEM.

if you can't hear the fuel pump cut in for a couple of seconds, check the fuse. Check the relay, or replace it with a known good one. See if you have power to the fuel pump. If you have power, your fuel pump is in need of replacement.
When you run an electric fuel pump out of gas, you should always cycle it about 10 times before you try to start the engine. That is, turn the key to on for a few seconds, and then off, and repeat. You need to get some fuel up to the engine.

you may want to check the engine's timing. You may want to check also the spark plugs as it may tell you if you are advanced or not. A black tip spark plug would tell you that the timing is late while a little white is advanced. You need is a light brown color. If there is no problem on the timing you may want to check on the fast idle control valve and pcv if it needs a little cleaning.

171 check, fuel supply system short circuit to b+
Check all positive (b+) fuel system electrical components. Injectors, fuel pump, regualtor, etc.

WARNING! Always wear protective eyewear, gloves and necessary clothing before inspection or work begins. Never crank an engine over when you are near the battery or engine. A battery is filled with explosive gasses that can ignite when extreme heat or a spark is present. A battery could have residual acid on the outside casing so use caution when handling a battery and the surrounding area. Use baking soda to neutralize any suspected acid residue before work begins.

You can check the car battery using a multimeter or voltmeter an electronic one is preferred , connect the black wire to the negative side (-) and the red to positive , WARNING :DO NOT CROSS THE RED AND BLACK WIRES OR SHORT CIRCUIT THE LEADS OF THE BATTERY OR MULTIMETER YOU CAN GET SERIOUSLY HURT!!!!! you should also get a spare watering can and fill it with water ,  (dont reuse for other purposes for safety) and remove those little tabs (usually around 4 or more) and fill it up very little in each tab/cap make sure you DONT fill it to the top. The good condition of a battery is 12.5 and 12.8 volts on the multmeter and when the car is started it
(not driven just started) should around 14V which shows that your alternater (acts as battery charger when driving) is working properly.

maybe the crank position sensor, long starts are usually due to the fact the computer doesn't know where the NO.1 cylinder is, so he fires at random and eventually he nails it, therefore the car starts.

The crank position sensor tells the computer where the NO.1 piston is at and he knows when to send the spark, but u should have a check engine light on in this case.

Your Vanos are shot. here's the link to Beisan Systems. They sell a DIY kit to repair the vanos. http://www.beisansystems.com/ or Dr. Vanos sells a rebuilt Vanos using the kit from Beisan Systems..... http://www.drvanos.com/ Either solution will address your issuel which one you choose is based on your mecahnical expertise...