1983 Mercedes Benz 380sl

Engine Mechanical problem
1983 Mercedes Benz 380sl V8 Two Wheel Drive Automatic 70,000 miles

When I first start the car it starts beautifully. After I drive the car and park it, I have to turn her over for 10 to 15 seconds before she starts again.
I have had 2 check valves replaced, warm up regulator, etc.
I will donate a small amout and it it fixes the proble I will increase it.
Been trying to fix this problem for 3 years now.
Driving mechanics crazy
March 19, 2010.

Hello .. thanks for the donation .. much appreciated

The thermo-time switch controls opening time of cold start valve. It is affected by engine temperature and starter current. Depending on coolant temperature (or engine temperature on air-cooled engines), the switch will take from 3-10 seconds to open. Injection through the cold start valve will then stop.
Some models use a hot start pulse relay to improve hot starting. While the starter is being operated, the relay allows the cold start valve to spray small amounts of fuel at regular intervals, until the engine is started.
If engine coolant is below 85 °F (30 °C), disconnect plug on cold start valve and connect test lamp across terminals. Remove coil high tension wire to prevent starting. Operate starter.
On models without hot start pulse relay, test lamp will light for several seconds, then go out. On models with relay, lamp will continue to flash off and on.
If lamp does not light, test thermo-time switch for continuity below opening temperature. If good, check wiring to starter terminal.
Remove cold start valve from manifold but leave fuel line connected. Place valve in a container. See Fig. 11 . Connect a jumper wire from one terminal to ground, and from other terminal of cold start valve to a switch. The other side of switch should be connected to a source of battery voltage.
CAUTION:Do not connect wire directly to battery. Extreme fire danger is probable due to atomized fuel. Sparks may result if wire is touched to battery.

Operate fuel pump. Turn switch to "ON" position. Cold start injector should spray. Turn switch "OFF", but leave fuel pump running. Injector should not spray. Wipe off nozzle and check for leakage. With pump running, no drops should form within one minute.
Fig. 11: Testing Cold Start Injector Valve After turning switch "OFF", injector should cease spraying fuel.

Replace cold start valve if faulty. Install original valve if good, making sure that "O" ring is properly positioned.

Hope this helps

Dave H
Mar 21, 2010.
Where can I get a Hot Start Pulse Relay? Where does it install?

Charles Glover
Oct 13, 2012.