Quote:
Originally Posted by cooljjay
I mentioned on the other thread....to clean the ground points on the car....guess this was ignored...
Before running out and buying stuff, clean the ground points and learn how the glows work..
I believe you are having other issues with the car besides the glow plugs. If injection timing is off, clogged fuel filters, leaking fuel lines, bad injectors, bad ground connections, worn starter, tight valves, bad battery cables can all cause issues relating to starting.
The early glow system, relies on temperature switch in the head to tell the relay when to operated and when to not operate. Unlike the later models that have the temperature switch built into the relay under the hood and sense the temperature under the hood. This is why the older w123's glow plugs don't stay or come on as long as the newer models.
The glows don't start the car, they simply heat the prechambers to combust the fuel. The starter builds the compression up in order for the fuel to combust. A good running engine will start with out the help of glow plugs.
Metal expands when it is warm and shrinks when it is cold. Thus there is a bigger gap between the rings and the cylinder walls the colder the engine is. The glows help heat this area to expand the metal...
These cars, take a multitude of things running correctly for easy starting and smooth idle.
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When I pulled the cluster a few days ago, those ground points were cleaned. I also cleaned the battery ground. This is really the only issue I'm having with the car (glow plugs).
The car starts perfectly, when the plugs actually come on. It runs smoothly and quietly. All fluids and filters are only about a month old. When the plugs don't come on, it takes a few seconds of cranking, especially when it's 50 degrees outside (like it is now).
I didn't even think to check the temperature gauge at the engine. I cleaned those contacts too, but it didn't seem to make a difference. Is it the one closest to the radiator or closer to the firewall responsible for glow plugs?
I also noticed that the glow plug light only ever comes on when the engine is cold. When it's warmed up, it never comes on. Below is a video of me attempting to turn the glow plugs on. The car was recently driven, but has been sitting for about 20mins. You can hear the relay clicking off at several points in the video. The engine is still warm, but the relay clicks off WAY too soon (around 23/24sec and again at 29). Notice how the battery light became more bright when the relay turned off?
There is a gremlin somewhere. At this point I'm thinking it's either the relay or the temperature sensor.
http://youtu.be/e9ubysouH3w
09-12-2014, 04:05 PM
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