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1990 300E Thermo Time Switch

6K views 7 replies 4 participants last post by  frobi 
#1 ·
Does the 1990 300E have a thermo time switch? If so, where would it be on the engine? I want to replace it as I have cold start problems. If not, what would be activating the cold start valve in cold and damp mornings? Thanks
 
#2 ·
What engine do you have?
Typically the cold start valve is activated by the fuel pump relay on the M103-12V or from the MAS on the M104-24V.
 
#3 ·
300E cold start



I have 124030 chasis and 103983 engine. I checked the MAS (opened it) and all solder joints were intact. I resoldered them stronger). My problem is that in the mornings or after 4-5 hours, I have to crank it 5-6 tomes before it starts to stumble, hasitate and slowly pick up the rev. Once it warms up, it runs very smooth and nice. All electricals ( plugs, ignition wires, rotor, dist. cap, battery, air filter, fuel filter) are new.
The 10 amp fuse in OVP is ok.
Thanks for responding.
 
#8 ·
I rewired the cold start with a push button switch and installed it near the foot cover on the left. When I want to start in the mornings or having it sat for hours, I press the switch for 3-5 seconds to open the cold valve to spray gas in the manifold. Is starts good. I had replaced the cold valve, temp sensor, MAS, but did not work.
 
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