Mercedes: car, fuel mixture, blended fuels

Question
my 190e 1992 mercedes will only start when it fills like it
do i need a new e.c.u. or do they have a cold start censer
I have taken the car to have it put on a pc. but they say
there is nothing wrong .if it fires first time then it starts
but if it fails to start  it then floods then it will take
ages to start or it may run the battery dawn fist.

Answer
Vince,
The vehicle may have a cold start injector that is acting up. It enriches the fuel mixture when the temperature drops. This is an additional injector just for the purpose of cold starting.
I would add Techron Black bottle injector cleaner to the fuel. The only problem here is that the treated fluid is only sent through the injector when it is cold. But it certainly should not hurt the problem.

I have had fits with my 420sel for the past winters. It got so bad last winter that the car sat for four weeks before I could finally get it to start.
We have has some pretty cold temps here in Georgia and it has started each time. I replaced the fuel pump control relay and the ignition switch since last year and have kept the fuel topped of.
I also make sure that the battery and electrical system are in good shape.
Corrosion on terminals and fuses is really a problem and when things get cold they shrink and you get bad connections and sometime high resistance in the sytem. Make sure you have the vehicle batter in very good condition and that the terminals are clean.
I would pause for just a moment after turning on the ignition before applying voltage to the starter. It may give the pumps time to pressurize the system before the injectors begin working. If you have taken on any bad fuel with water that can play havoc with your starting.  The new alcohol blended fuels are susceptible to absorbing water from the air, this can end up in the tank and become a problem particularly if you allow the fuel level to get low.
I hope this helps.
Good Luck
Rob