cold start issue

[jerseybenz]

New to the car. When cold, it takes about three times to fire up but immediately after that it will start up instantly unless it sits for hours. Would you experts suggest the cul;prit is the cold start relay? I was thinking maybe a lack of fuel pressure.

[Raymond]

The easiest thing to try is turn on the ingnition (to start the fuel pump) and wait about 15 seconds to be sure there is good fuel pressure.  Then, there is a whole list of things that could be affecting this before you get to the cold start valve. 

An easy check for the CSV is to run a wire from the battery and touch the lead screw on the CSV.  If it clicks, the relay in it is working.  If you have an assistant, you can listen for the click when the ignition is first turned to "start".  Next you can confirm it's getting gas by loosening the fuel line nut just a bit and turn on the fuel pump.  If it leaks, you'll know gas is getting there. 

Search the fourm for Cold Start problems and you'll find hours of reading fun.

[George Des]

When I start my 230SL from cold, I let the fuel pump run for a few seconds as Ray says. When I crank it over, I do not press the accelerator pedal. it will usually start right up. Restarting when hot is slightly different though. I press down and hold the accelerator while cranking and it'll start right up. Hope this helps.

George

[jerseybenz]

I should have mentioned my car is a '69 280sl. I have tried waiting for the fuel pump, that's not the issue. Like I said, starts instantly after it's been run, even like 1 to 2 hours later, but when cold, I crank it three times before she fires up. The car has electronic ignition which my local benz expert tells me is a good modification.

I'll try a search on the subject but if the CSV is not the next likely culprit what is?

[Olazz]

JB,

Interested in this fix as my car has the exact same problem. It was fine when I had normal dizzy in with points, but started to behave this way after I installed a 123 dizzy.

Recently installed a new fuel pump  which has made it better, but still have to crank it twice/three times when cold. Starts on the button once it been started once.

[ctaylor738]

I recommend first testing the electronics by connecting a test light between the CSV wire connection and ground.  If you don't get a light while cranking when cold, you need to check the wiring and the thermo-time switch.  If you do have a light, then the CSV may be plugged.  So remove it and reconnect it so that it squirts into a jar or plastic bag, and crank the starter.  If it doesn't have a healthy spray, you need to replace it or get it cleaned.

[ja17]

Most likely you have two starting aids on the 69 280SL.  As Chuck has mentioned first check them both with a test light.  The top solenoid on the injection pump should activate anytime the starter is engaged. 

Next the CSV (cold start valve ) on the intake manifold should activate when the engine is cold.

Check both and get back with us for the next step

[rbradley]

Re Cold start subject, I have spent most of my wk end exploring the CSS on my 1971 280.
I have never had a cold start problem and was surprised to find the system was non- functioning.
I found this as I was replacing the WRD which was not shutting off the air supply to the manifold.
After I had completely tested and reconnected the CSV and the temp switch as well as the cut-off
switch I took the car for a brisk spin and I believe the car was smoother and seemed to run better.
I then left the car outside to test the CSS, it being 45 degrees. The car refused to start after several
tries. Only when I pulled the plug on the CSV relay would it start.
My car also runs rich with black soot on start- up but no other driveability issues. My theory is that
it  is so rich to begin with that a correctly operating CSV merely causes the engine to flood.
Sorry to be so long winded but this is my first post. Any thoughts or suggestions on my richness
issue?

[Larry & Norma]

My car used to run very rich on start up, lots of black soot etc.
I did the linkage set up and adjusted the IP using a CO measuring
device. It is fine now and always starts easily.

[ja17]

Is your WRD now functioning correctly ?  Next Are you familiar with the "Split linkage CO test" ?