W109 300SEL 3.5: How can I set ignition timing?

[werminghausen]

I have adjusted cam timing and want to adjust ignition timing now.
How can I set ignition timing before the engine is running? And then how can I fine tune it after the engine is running? I am close to start the engine. I have the inductive light.
Martin

[wbain5280]

Set the engine to TDC, align the crank and camshaft slots. Then make sure the distributor rotor and the notch on the distributor body are aligned. Go from there.

Have you upgraded the points to Pertronics, HotSpark or some other modern replacement?

[GGR]

As said by Warren put your cyl. 1 at TDC, ignition stroke. For that check through the oil filler cap if both cams are facing up. If not rotate the engine 1 full rotation. When you are there make sure the rotor is facing the HT lead of cyl.1.

If you have a euro version (Bosch dizzy no 0 231 302 001 or 0 231 401 001) the value are the following:

Starting (cranking) speed with spark plugs without vacuum: 10 deg BTDC;
Idling speed with vacuum: 3 ded +/- 1 ATDC;
1500 rpm without vacuum: 12-20 deg;
3000 rpm without vacuum: 34 deg;
4500 rpm with vacuum: 34 deg;
Ignition timing vacuum control toward retard at idle speed: 7-13 deg.

If you have a US version with exhaust emission control (Bosch dizzy no 0 231 302 002 or 0 231 401 002) the value are the following:

Starting (cranking) speed with spark plugs without vacuum: 10 deg BTDC;
Idling speed with vacuum: 6 ded +/- 1 ATDC;
1500 rpm with vacuum: TDC +/- 1 deg;
3000 rpm with vacuum: 30-38 deg;
Ignition timing vacuum control toward retard: 18-22 deg.

[mak]

Hi Martin
Have you got the air suspension all fixed as well with the new valves you made .
regards
mak

[werminghausen]

Originally Posted by wbain5280

Set the engine to TDC, align the crank and camshaft slots. Then make sure the distributor rotor and the notch on the distributor body are aligned. Go from there.

Have you upgraded the points to Pertronics, HotSpark or some other modern replacement?

I have done what you just said but was not sure about it. Thanks so much.
I guess this is a start at least. I was as precise as I could but lining up up means guessing to a degree because the distributor and the notch on the housing are some distance apart.
Also I can move the distributor slightly forth an back therefore I am not sure if this is how it should be.
I also tested the vacuum membrane- seems to work and it moves the plate where the points are.

I guess if I stick to the points i need to use the inductive light to fine adjust the ignition timing?

I haven't upgraded to Pertronics. What does this mean?

Martin

[werminghausen]

Originally Posted by GGR

As said by Warren put your cyl. 1 at TDC, ignition stroke. For that check through the oil filler cap if both cams are facing up. If not rotate the engine 1 full rotation. When you are there make sure the rotor is facing the HT lead of cyl.1.

If you have a euro version (Bosch dizzy no 0 231 302 001 or 0 231 401 001) the value are the following:

Starting (cranking) speed with spark plugs without vacuum: 10 deg BTDC;
Idling speed with vacuum: 3 ded +/- 1 ATDC;
1500 rpm without vacuum: 12-20 deg;
3000 rpm without vacuum: 34 deg;
4500 rpm with vacuum: 34 deg;
Ignition timing vacuum control toward retard at idle speed: 7-13 deg.

If you have a US version with exhaust emission control (Bosch dizzy no 0 231 302 002 or 0 231 401 002) the value are the following:

Starting (cranking) speed with spark plugs without vacuum: 10 deg BTDC;
Idling speed with vacuum: 6 ded +/- 1 ATDC;
1500 rpm with vacuum: TDC +/- 1 deg;
3000 rpm with vacuum: 30-38 deg;
Ignition timing vacuum control toward retard: 18-22 deg.

Forgive me for my ignorance.
This is my first W109 and I have no clue what you are saying.
What I am reading... I first need to find out the version I have: Euro or US.
I looked at the number at the distributor cap...it is 1235522061.
Where can I find the Bosch numbers you are referring to? Or how can I find the version my engine is using?
On the plate at the radiator it says: Timing 6 deg. ATDC at 800 rpm vacuum line connected, co- setting 1.5 - 3 %..if I read correctly... I guess I have the US version then with emission control.

I think for the test I need to get the engine started (It is not running right now but I am planning to give it a try soon when all components are installed. It has been 2 years now).
I also guess that I need the inductive light and then measure at cylinder 1 spark plug. (I have a light)
With/without vacuum means connect/disconnect the vacuum line to the distributor?

Why are there so many values? I mean which one do I use to adjust.
After what I read on the plate I am using the 6 deg. after TDC at idle /800rpm
is this correct?

How can I see if the breaker points are still good? I read about adjusting the closing angle or dwell angle but I don't know what this means.
How can I measure the closing angle?


What does the upgrade from breaker points to pertronics mean?
Thanks, Martin

[JMela]

Martin, Pertronix is a manufacturer of electrical units that replace the points setup in your distributor. It's a popular upgrade around here and eliminates the hassle of dealing with points. Here's a basic rundown for a different Mercedes vehicle:

http://www.mbzponton.org/valueadded/maintenance/ignitionpert/ignitionpert.htm

[GGR]

Martin, you have a US version, so you have to use the second set of values I posted earlier. The dizzy p/n is on the body, not on the cap. But unless you suspect the dizzy has been replaced earlier in the car's life, just go with the US specifications. Won't change much anyway.

Pertronix is a nice upgrade. But unless one of your elements such as the resistor box is bad, I would first have the car run propely on the stock trim and then upgrade.

You should check if your cetrifugal advance works properly by moving the rotor. You should feel the spring's resistance and the rotor should come back to it's initial position under the action of the springs.

You should then check if your vacuum advance/retard works properly. For that you should suck into the hose connected to the vacuum capsule and check if the plate on which the points are fitted is moving and going back when you stop applying vacuum. Check also that the rubber connection of the vacuum line to the throttle body is not worn, as this is quite common. Also check that the butterfly closes properly and that the system goes back up to the stop nut when the gas pedal is not operated (idle is not adjusted there but with the big screw near the cold air valve).

If you can measure dwell then you should adjust it to 30 degrees while intalling new contact points. Inspection value of used contact points is 34 degrees.

If you cannot measure dwell you should adjust the gap at 0.4mm. For that you can loosen the dizzy until the contact is right on the hedge of a cam. There the 0.4mm gage should move relatively freely with some light resistence.

Once you've done that you should clamp your stroboscopic lamp on the cyl1 HT wire. Engine running and vacuum line connected, rotate the dizzy until you read 6 degrees ATDC at 800 rpm. You may have to adjust idle during the process.

Then ask someone to press the gaz pedal and stabilise rpm at 1500. there you should read TDC. Then accelarating aegine at 3000 rpm you should read a value comprised between 30 and 38 degrees.

Marking the needed values with white corrector on the damper will ease your readings.

Go for a test drive and make sure the engine is not pinging. You can see that with a warm engine uphill on the last gear around 2000 rpm while opening the throttle widely. If it does ping then reduce advance until it does not ping anymore. Use the highest octane fuel you can find.

[have mercy]

If you have points. Get the engine to top dead center. wire to dis. install a test light,1on + the other to points. turn dis. untill light just comes on .that will get you real close.

[werminghausen]

Originally Posted by GGR

Martin, you have a US version, so you have to use the second set of values I posted earlier. The dizzy p/n is on the body, not on the cap. But unless you suspect the dizzy has been replaced earlier in the car's life, just go with the US specifications. Won't change much anyway.

Pertronix is a nice upgrade. But unless one of your elements such as the resistor box is bad, I would first have the car run propely on the stock trim and then upgrade.

You should check if your cetrifugal advance works properly by moving the rotor. You should feel the spring's resistance and the rotor should come back to it's initial position under the action of the springs.

You should then check if your vacuum advance/retard works properly. For that you should suck into the hose connected to the vacuum capsule and check if the plate on which the points are fitted is moving and going back when you stop applying vacuum. Check also that the rubber connection of the vacuum line to the throttle body is not worn, as this is quite common. Also check that the butterfly closes properly and that the system goes back up to the stop nut when the gas pedal is not operated (idle is not adjusted there but with the big screw near the cold air valve).

If you can measure dwell then you should adjust it to 30 degrees while intalling new contact points. Inspection value of used contact points is 34 degrees.

If you cannot measure dwell you should adjust the gap at 0.4mm. For that you can loosen the dizzy until the contact is right on the hedge of a cam. There the 0.4mm gage should move relatively freely with some light resistence.

Once you've done that you should clamp your stroboscopic lamp on the cyl1 HT wire. Engine running and vacuum line connected, rotate the dizzy until you read 6 degrees ATDC at 800 rpm. You may have to adjust idle during the process.

Then ask someone to press the gaz pedal and stabilise rpm at 1500. there you should read TDC. Then accelarating aegine at 3000 rpm you should read a value comprised between 30 and 38 degrees.

Marking the needed values with white corrector on the damper will ease your readings.

Go for a test drive and make sure the engine is not pinging. You can see that with a warm engine uphill on the last gear around 2000 rpm while opening the throttle widely. If it does ping then reduce advance until it does not ping anymore. Use the highest octane fuel you can find.

Thanks so much, this is very helpful information
I have no idea how to measure the dwell angle (so if you know how can I measure this angle in theory properly? ... so I can go and measure the max. gap of the breaker points of 0.4mm with a feeler gauge and adjust if needed.
I'll also check the vacuum line to the dis. The membrane works and is moving rotating the plate in the distributor fine. I have moved the distributor arm back and forth and it is moving and moving back when i release the arm.
I can't really test drive the car right now as I have the air valves removed for renovation. I hope to have the valves ready in couple months.
But I can't wait until I hear the engine firing. I haven't heard it since 2 years when I started major rust repair.

[GGR]

You need an apparel to measure dwell. I don't have it and always use the feeler gauge. It works fine.

You can do all the process without test driving the car. Just keep in mind you may have to reduce advance if you hear it pinging when you drive it.

Ignition is the first thing to look at. But you may have to look into the Djet system if your car did not run for two years. Flush the old gas, check all the rubber fuel hoses, or best replace them. Djet systems are famous to set cars on fire due to older hoses cracking with gas squirting under pressure all over the engine bay and then being lightened by the heat of the exhausts manifolds. Then check if the fuel pump delivers enough flow and pressure. If you have other issues there are true D-jet specialists on this board who will help you.

[werminghausen]

I have replaced all rubber fuel lines in the engine bay.
I guess the injectors are kind of dry now....what can I do? Is there any cure before starting or should I just fill in new fuel and start the engine?

[GGR]

You can try to start the car like that and see how it goes. Otherwise Cruzin' Performance does a good job in cleaning injectors for a reasonable price: http://cruzinperformance.com/

[werminghausen]

Originally Posted by GGR

You can try to start the car like that and see how it goes. Otherwise Cruzin' Performance does a good job in cleaning injectors for a reasonable price: http://cruzinperformance.com/

I checked the breaker point gap yesterday...was very close to 0.4mm. So I just let this go and I will try and start the engine this upcoming weekend. See how it goes. Thanks so much for the info. Martin

[GGR]

You're welcome! Keep us posted on how it goes.