Pagoda SL Group

W113 Pagoda SL Group => Electrical and Instruments => Topic started by: Allforjags on November 05, 2019, 16:37:37

Title: 280 sl Coldstart problem
Post by: Allforjags on November 05, 2019, 16:37:37
Hello
My 280 sl is kranking 15 sec before it starts.Does anybody knows is that normal.
When i connect the testlight to CSV terminal and ground light starts when i start kranking the motor but light wont stop .I read that light must work only from 2-12 seconds.
Any ideas..
Title: Re: 280 sl Coldstart problem
Post by: teahead on November 05, 2019, 16:50:56
Hmm...bad thermo time switch?  Or relay?

You can bench test the relay.  See if the output stays on when you apply power.
Title: Re: 280 sl Coldstart problem
Post by: Cees Klumper on November 06, 2019, 04:09:19
Could be that the cold start valve is clogged. Or maybe the thermostat in the Warm Running Device (little tower on top of fuel injection pump, with coolant hoses attached) is stuck with the rod in the extended position.
Title: Re: 280 sl Coldstart problem
Post by: ja17 on November 09, 2019, 15:54:44
The solenoid on the injection pump should stay on while you are cranking the engine. You are correct in that the CSV on the intake should only stay on for a timed period. Test both devices you may have a wiring issue.
Title: Re: 280 sl Coldstart problem
Post by: Benz Dr. on November 09, 2019, 16:16:03
Quote from: Cees Klumper on November 06, 2019, 04:09:19
Could be that the cold start valve is clogged. Or maybe the thermostat in the Warm Running Device (little tower on top of fuel injection pump, with coolant hoses attached) is stuck with the rod in the extended position.

Good call Cees. A plugged CSV is more common that one would think or expect. Sometimes only one side is plugged so if you're having problems with cold starting check the CSV by removing it and visually inspecting its performance.
Title: Re: 280 sl Coldstart problem
Post by: wwheeler on November 09, 2019, 16:17:46
There was another thread where someone had confused the operation of the CSS (Cold Start Solenoid) that is on the injection pump with the CSV (Cold Start Valve) which is on the intake manifold. I wonder if there is confusion here with the acronyms? As Joe said, the CSS should stay on the entire time the engine is cranking. And 15 seconds is way too long to start for a well sorted engine.
Title: Re: 280 sl Coldstart problem
Post by: ja17 on November 09, 2019, 20:52:06
The intake fitting for the cold start valve, on the intake, has a fine screen in it that can get clogged also. It's easy to check to see if the screen or the cold start valve jet is clogged. With the warm engine at idle, just jump the CSV with 12 volts for an instant. If the CSV is spraying fuel, then the engine will stall.