Thermo Timer Switch

[glcg123]

My 230Sl was starting nicely, cold or hot and has been for the past few years. We have had a hot spell and I did not drive it for about 10 days. Go to start it and it will not start. I can get it to start by using a test light from a ground to the ground screw on the CSV solenoid. The car ran rich and stumbled. It started well when warm. Now I understand that the TTS provides ground to the CSV circuit so that could be the problem. Also, there are a couple wires running from the TTS to a solenoid on the fuel pump. Could that be the source of the fuel mixture issue? I have tried testing the TTS using the W and G posts with a jumper cable and test light. The test light stayed on for about a second. With all the heat here the garage is hot. Should I test again when cooler?  Can the TTS suddenly fail? I have tried measuring resistance and I get 0 ohms across the G and 0 across the W. Am I doing something wrong?

George 1965 230SL 4 speed

[glcg123]

I have figured out my problem, fuel issue. I crack the fuel line at the CSV and the car starts. It runs lean causing the stumble. So, off to my mechanic to check the tank pump, tank and lines. I remember having this issue 17 years ago when I got the car. The tank was relined then. Perhaps a mesh filter is plugged, etc. Also, the relining material may have failed causing the problem. We will see.

[Pawel66]

Just in case: the easy thing to check is the fuel flow at the end of the return line, should be 0.8-1liter in 15 seconds.

Also: there is a screen in the fuel tank, screen in the inlet of the fuel pump and the main filter in the engine bay.

It is a good practice to install an in-line filter between the tank and the fuel pump, especially if you do not have the screen in the fuel pump.