dieseljunkie201

Can anyone tell me what position is #1 on a M103 distributor cap please?

I know the firing order but, I can't figure out how the wires go on the cap. I have tried searching this forum for quite a long time and the mercedesshopforum as well... Please, someone go out to their 300E and tell me which terminal on the distributor the #1 wire goes on.

i6h000

Don't have a 103 motor but look closely, the #'s should be on the cap.

ohlord

engine straight on trace a line from the oil cap to the upper part of the distributer with your finger.If the oil cap handle is inline with the engine as it should be the line you imagined will end up between the top two plug wire towers on the dist cap.The one on the right side of that line is plug 1 to cylinder 1 in the firing order.The shortest wire.

radioray

look at the distributor cap cover(the black plastic cover piece you put on before the wires) it shows the firing order. firing order is 6 2 4 1 5 3 clockwise. good luck

dieseljunkie201

Thanks for the info, got it figured out, the car ran great but....

The old problem resurfaced, when it gets warm (not at a specific coolant temp but maybe egt) it runs really poorly and dies... WTF!

Quicksilver500

Check your over voltage protection relay is behind the battery and can cause stuff like that.

dieseljunkie201

That's what I was thinking. The ABS light also flickers, but my tech said that it almost irrefutably the crankshaft position sensor.

ohlord

engine coolant temp sensor check both.
Any blinks on your blink box?
Have you ever replaced the o2 sensor?



To the poster above giving instructions on firing order I hope for sure he learns number 1 cylinder is number 1 in the firing order of 153624
reading something as convoluted as he posted could lead some newb down a path of misfire that would not be fun.

190E 16V

Oh, Lord;

Off topic, but have you checked posts by "Jason" in NY?

He has a 500E that he says he is putting an E55 drivetrain into.

He could use your help.

ohlord

A buddy is putting all the sheet metal and the engine of a 500E into a 1994 w124 wagon. But a 55 into a 500e I hope he got the whole donor car. He will need all the running gear from engine harness ignition trans ecu tcu sensors.
At least he is keeping it in the family and not sticking in a 2JZ

radioray

Does anyone know if there is a program i can run on a laptop to diag port in my 1990 300e w/ a 103.983 3.0L engine for checking sensor parameters ? I want to see whats doing on

radioray

The firing order your giving is corect but, looking clockwise at the cap #6 is the first terminal starting at the 8:00 o'clock position so knowing the first term # the rest is simple. knowing where any one position is you can figure the rest w/ the firing order.
8 o'clock is a good place to start with that kind of cap design.

dieseljunkie201

Thanks, the firing order is all correct, no need to worry I just needed to know where to start putting on wires... But more importantly, my car doesn't have a LED on the blink box, so I would have to make a tool, also I was told by a trusted source that my symptoms are indicative of crank position sensor failure. I am also considering the OVP, is there a way to test either of these?

radioray

Issues with the ovp relay, It is behind the battery. It has either one or two fuses on the top. take it out, take the cover off and look at all the terminal solder connections for loose or broken leads.The crankshaft sensor will be an open circuit if good,flex the base of the wire from sensor to see if you have any change in your readingsif so it is shorting to ground and needs to be replaced. good luck

86560sel

Is there any way to test the crank position sensor and where is it located on a M103 (W126)?

Thanks