Cold start problems? Check your battery.

[ctaylor738]

My 230SL is (or was) very predictable.  Cranks for 1-2 seconds cold, starts, and has to be held at 1000-1200 rpm for 20 seconds before it will idle.

Yesterday I went to start it and found an almost dead battery.  I put the charger on it overnight and today was emabarassed to find a very loose alternator belt.  So I tightened that up.  I put the meter on the battery and saw that I had about 12.5 volts.

Turned the key and the car started instantly and idled without any need to keep the revs up. 

What I think is happening is that especially in warm weather, the CS valve and solenoid are not engaged for very long.  The starter is taking most of the power, and if the battery isn't strong, the fuel needed for start enrichment won't get delivered.

[mdsalemi]

That goes into the "Hmmmm....." department.  Nice find Chuck, and glad you discovered a solution.

[ctaylor738]

It's now been a couple of weeks since I tightened up the alternator belt.  The car is definitely doing better in post-start idle.  It will now start and idle, no need to keep it at arround 1100 rpm for 15-20 seconds.  The warm up running is also better, but the change is not as marked.

[Benz Dr.]

Low battery and charging voltage could have been affecting fuel volume and pressure. I would start looking at idle mixture next.