68 280SE Firing sequence ??

[Markken2008]

Hi There

I have a 1968 Mercedes 280 SE and during an overhaul the leads from the distributor cap to the spark plugs got mislaid .
Does anyone have a diagram of the settings for the leads from each of the points of the cap to the spark plugs....

Or can you explain how I know which goes where ?


I set them as I thought was correct and the car starts but it only ticks over for a few seconds and then conks out


any help or advice would be much appreciated

Thanks Mark

[Markken2008]

just read the direction on how to post :-) Car is a 280 SE Automatic Saloon petrol version , 6 cylinders , firing order 153624 , Engine M130 ,Chassis Number 108.018.22 018549 . Engine Number 130980.22 013780 ,Registered February 1969

[Mike D]

Double check your coil wiring. You have a "start" circuit (power is supplied from the starter while cranking) and a "run" circuit (power is supplied by the ingition in the #2 position).

The "run" circuit is usually supplied through the ballast resistor and is reduced to apx 8 volts. Check the battery (+) terminal on the coil with the key in the #2 position.

The "start" circuit is 12 volts supplied directly from the starter solenoid only while cranking.

[Markken2008]

Thanks Mike but my actual question is slightly different


I am trying to find out how I know where each of the spark plug leads goes on to each of the points on the distributor cap

I am fairly sure that the error is with the leads as the car was running fine with the leads in place as they were ......problem started when the leads were disconnected and misplaced

[Todd Miller]

So you've got the firing order.

Now remove the distributor cap from the distributor body. Look down at the surface of the dizzy body, where the cap was mated up. Standing in front of the car, looking down at the dizzy, you'll see a line scribed at about 3o'clock (if 12o'clock is the car's windscreen). That mark is the position of #1 spark plug wire on the dizzy cap. From there, install the plug wires into the cap, [edit]clockwise, in the firing order that's printed on the valve cover.

In the future, there's never a reason to remove the plug wires from the dizzy cap, except when replacing the leads...and when you do that, you do them one at a time so as not to lose track of where they belong. It'll save you a ton of time!

[mbgingerbread]

Hi..
You have to explain 'ticks'. The above posts reflect correct procedure for finding your way to the truth...
If your car starts you might have a fuel problem as opposed to an electrical one.
You can remove your distributor cap and look for a mark on the lip of the distributor-this normally represents #1 cylinder. Crank your engine and when the tip of the rotor button is aligned with that mark you can check the timing marks on the flywheel-you should be at TDC. I use a compression tester in the #1 cylinder hole to ensure that I am on the compression stroke (The point at which the fuel and air mixture are getting ready to do their 'explosion thing') I also use a 27mm socket to finesse the tining marks to TDC. I Then start with the #1 plug wire above this mark on the distributor cap and then take the firing order from there clockwise as you look down at the top of the cap. You should be able to connect each wire at the distributor cap end with the right spark plug which of course represents the cylinder to be ignited!. Good Luck

[Arthur Dalton]

< From there, install the plug wires into the cap, counter-clockwise, in the firing order that's printed on the valve cover.
>

Don't do that ..the rotor turns CW .

280 SE Spark Plug Leads ? where do they go

[Markken2008]

Thanks for the input and advice very helpful ...one last question (hopefully ) the correct path is to install clockwise and not CCW ?

[Arthur Dalton]

Originally Posted by Markken2008

Thanks for the input and advice very helpful ...one last question (hopefully ) the correct path is to install clockwise and not CCW ?

Correct...you want the rotor to follow the firing order, so just start at #1 and install the next sequenced # of the fire order on the cap CW.
Then , when the rotor turns , it will be firing the Correct plug according to the correct Firing Order.

You probably have a couple crossed if all that was done was the wires removed..happens all the time.
Only if the dist was removed would you then you have to contend with the TDC and compression stroke stuff.
You are not timing anything, you are simply asking where the plug wires go back into the correct cap towers.

Fig #2 at this site is like your chassis.

https://www.autozone.com/az/cds/en_us/0900823d/80/21/4a/86/0900823d80214a86/repairInfoPages.htm

[Markken2008]

Sorted now .......Thanks Arthur your advice was truly invaluable ....

[Arthur Dalton]

You're Welcome..............

[Todd Miller]

Sorry about the mis-information guys and thanks for steering him right....errr, clockwise!

[Arthur Dalton]

Originally Posted by Todd Miller

Sorry about the mis-information guys and thanks for steering him right....errr, clockwise!

You are just so used to working so many hours on your car from underneath ...that explains the CWW ...

[Todd Miller]

Actually, I was thinking, "If the vacuum retard is coming in from the left....." But I forgot; it's lever is pulling on the bottom of the distributor plate, so it's pulling the plate MORE clockwise in order to retard, and not more counter-clockwise.

OOPS!

[Arthur Dalton]

Correct .......that system is Vac Retard, with Mechanical Advance.
Only the earlier MFI had Vac Advance.