1972 280SE 4.5 timing-pertronixII-disrtibutor

[Adv_rider]

Hi guys, I've been reading a lot the last 5 days and I would like to thank you all for teh information .. it has been extremely useful.

W108 1972 280SE 4.5L

My problem:

Installed Pertronix 91885 (Ignitor II & Flamethrower II) -; red to (+), blck to (-) on coil.. and ignition 12V (before resistance) to coil (+)
Removed MB system.
Check resistance from dist. plate to batery - and had 0.2ohms which is correct.
Voltage to coil is 12V with switch to on position.
Spark plug cables are Bosch Ultra.... cooper wires (which AFAIK are not solid core, but im not completely sure)

Set TDC at cyl 1 and 0 at crank. made sure is at compression. (remove cover and align cam marks)
I removed distributor (0231402002) to clean and install ignitor and reinstalled with rotor aligned to lip mark and made sure spark cables are set accordingly to fire order.

Car was working ok with points.

Now Car wont start!!! ...If I rotate distributor to extreme CCW it would start barely, but I run out of the location screw.

I tried reinstalling with one tooth of rotor either way but it doesn't work.

Should I use iginitor I instead?

Any ideas?

Should i reinstall distributor with Crank at 10ATDC? or 10 BTDC? .. or it should always go in at 0 TDC?

PS: The black rotor seats lower than ignitor module .. not leveled on top. (guys at pertronix said not to worry .. ?¿?)

Merry christmas

[meltedpanda]

it sounds like your pertronix is set up correctly

Go back and recheck the distributor location, and wires ..many of us thought we had it right - but found out otherwise.. dont ask me how I know

[Adv_rider]

Originally Posted by meltedpanda

it sounds like your pertronix is set up correctly

Go back and recheck the distributor location, and wires ..many of us thought we had it right - but found out otherwise.. dont ask me how I know

Thank you. Yes i will do it again.... today I bought ignitorI and Flametrwr I which will be receiving some day next week..

It will be my 10th time, but will keep on trying.

Can I install distr. at 10ATDC? ... Or it should always go at TDC?

[meltedpanda]

with number one cylinder at TDC the first plug wire should line up to receive spark, put your rotor back on to confirm, TDC or 0 mark on the timing reference - not only do you need to line up the timing marks, but you have to make sure the piston in #1 cylinder is at the top of its compression stroke.

[Adv_rider]

Originally Posted by meltedpanda

with number one cylinder at TDC the first plug wire should line up to receive spark, put your rotor back on to confirm, TDC or 0 mark on the timing reference - not only do you need to line up the timing marks, but you have to make sure the piston in #1 cylinder is at the top of its compression stroke.

I used the mark in the cam as reference to set cylinder 1. I noticed the lobe is not really pointing up, it's more like at 2 o/clock. Is that correct?

[meltedpanda]

trace 1st plug wire to cap then place cap on distrb. then place distributor - make sure the 1st cylinder is at TDC

[Graham]

Originally Posted by Adv_rider

I used the mark in the cam as reference to set cylinder 1. I noticed the lobe is not really pointing up, it's more like at 2 o/clock. Is that correct?

The lobes for cyl 1 should look like rabbits ears - both pointing up at about 2 and 10 oclock. Crankshaft should be close to TDC mark. With rotor in, it should point approximately to mark on distributor at about 1 oclock.

Your distributor should be turned all the way CCW until it comes to end of slot, then back about 1/8". That should give you good place to check timing. It should be about seven degrees before top dead center with all vacuum hoses disconnected from the distributor and plugged. Then check at 3000rpm and it should advance further to about 27-30 BTDC.

Those Bosch wire you have are copper cored and should work fine. The Pert Ignitor I (1885) is the recommended unit for these cars.

If you can't get car to run, first check that all plug wires are correctly connected. We have all done that wrong.

Also make sure the Pertronix is correctly connected. The diagram that someone once posted is in this link:
Ignition - Benzworld.org - Mercedes-Benz Discussion Forum

Finally if all else fails, try going back to original points setup with MB switchgear and see if you can get her running.

[Adv_rider]

It's alive... It's alive!! Muahahahaha!

Thank you all for the help.

Strange, but here us how it worked in case anybody is on the same situation. I'll try my best to describe it.

As I've been doing for the last 4-5 days....Cyl 1 and crank at TDC, Insert distributor with rotor aligned to lip... BUT instead of distributor & rotor pointing at 1 o'clock like graham said (and like I have been doing), I insert it more like at two o'clock!... Of course still rotor and distributor lip mark aligned, and cyl 1 cable on top.

It's important to mention that this way the distributor base is off of the location hole! After inserting the dist. I had to rotate it CCW (pointing to 1 o'clock aprox.) in order to be able to insert the locking screw.... With the screw on, the dist is rotated to the max possible CW.

My dist is 0231401002, not as I reported on the op 0231402002.


This way the car started right away!!! But iddle was kind of high.

Since this distributor lower plate can be adjusted, I removed it and rotate the base CCW as far as possible. This gave me more clearance to adjust timing.

Anyhow still a little high at iddle, I'm very happy it's working and te engine sounds really good. Can't beleive it has 40 years... Sounds like 2.

Still have to check timing

Merry Christmas everybody.

[Palolo]

Originally Posted by Adv_rider

Congrats. Good feeling, yeah?

I can't believe there's a Gangnam Style smilie on here. The places that's gone...

[meltedpanda]

good for you ,
I have offered this "wisdom" before...if somethiong was working before you did a repair or replacement , and now doesen't go back and do it over...regardless of ones "i'm positive I did it right" feeling

Been there , done that so many times, lol

Also next time - before you remove dizzy mark the location of the notch where the rotor sits directly on the housing of the distributor. Use a white marker .
It will save you a lot of grief

[Graham]

Originally Posted by meltedpanda

Also next time - before you remove dizzy mark the location of the notch where the rotor sits directly on the housing of the distributor. Use a white marker .
It will save you a lot of grief

If I understood correctly, he was starting at 1 oclock when inserting distributor, but of course it rotates on the way down as the gears engage. It has to end up at 1 o'clock!

There should have been no need to change the plate on the bottom of the distributor. With it centered in the slots, the clamp bolt should have ended up almost at the end of it's slot when the timing is set right. In other words, distributor rotated almost completely CCW.

Good that car now runs though

Merry Christmas and/or Happy Holidays to all!

[Adv_rider]

Originally Posted by Graham

If I understood correctly, he was starting at 1 oclock when inserting distributor, but of course it rotates on the way down as the gears engage. It has to end up at 1 o'clock!

There should have been no need to change the plate on the bottom of the distributor. With it centered in the slots, the clamp bolt should have ended up almost at the end of it's slot when the timing is set right. In other words, distributor rotated almost completely CCW.

Good that car now runs though

Merry Christmas and/or Happy Holidays to all!

Not exactly.

When the dist and rotor settled in at 1 o'clock... The car won't start. Even if I rotated to the max CCW. IT would barely.

So I inserted dist one notch to the right ( the lip is a little off to the left of the rotor center but not
Much) ... And settled in it would be like at 2 o'clock. The dist is rotated to the max CW... It started right away. .... So I slip the base which allows me to rotate the dist further CW and allowed me more room for timing.

[meltedpanda]

Graham, Adv rider
Merry Christmas to you too..
at least it is running, without seeing it tough to tell the exact movements made. That is why I mark the rotor , inside the dizzy
in any respect - one more on the road!
BTW - ADV , in case you did not know - Graham is the DJET guru , bar none..

[Graham]

Originally Posted by Adv_rider

Not exactly.

When the dist and rotor settled in at 1 o'clock... The car won't start. Even if I rotated to the max CCW. IT would barely.

So I inserted dist one notch to the right ( the lip is a little off to the left of the rotor center but not
Much) ... And settled in it would be like at 2 o'clock. The dist is rotated to the max CW... It started right away. .... So I slip the base which allows me to rotate the dist further CW and allowed me more room for timing.

There is a mark on the distributor. Rotor should point to it. (1 oclock 2 oclock,,,,?) When you are doing this, are the marks on the camshaft and on the crankshaft balancer both aligned? If they are, that would be good, but not very common unless the timing chain and sprockets are brand new.

I would think that if the crankshaft is at TDC mark, then the distributer should be aligned as it was when new without having to change that plate on bottom. The engine should start over quite wide range of adjustment on that curved slot, not just at one end.

Its good that you got it running, but it may be an idea to now try and get back the way it was originally. Makes future tuning and troubleshooting a lot easier.

[Adv_rider]

Originally Posted by Graham

There is a mark on the distributor. Rotor should point to it. (1 oclock 2 oclock,,,,?) When you are doing this, are the marks on the camshaft and on the crankshaft balancer both aligned? If they are, that would be good, but not very common unless the timing chain and sprockets are brand new.

I would think that if the crankshaft is at TDC mark, then the distributer should be aligned as it was when new without having to change that plate on bottom. The engine should start over quite wide range of adjustment on that curved slot, not just at one end.

Its good that you got it running, but it may be an idea to now try and get back the way it was originally. Makes future tuning and troubleshooting a lot easier.

Thank you, and yes I'm wondering the effects this may have since I can't fully comprehend why ... It beats me why the timing (or should I say the point where I can start the engine) is between two distributor notches. Maybe is not the correct distributor?

Question: to install the distributor, which is more important to consider cam at mark or crank at OT?

I will try to re-explain what I did:

Assuming these variables are the same:

1. Cyl. 1 at compression - mark at cam as close as possible when crank at OT
2. crank at OT mark
3. Spark plug cables checked according to firing order. And 1 on top of rotor point.

Position A is the distributor installed where the locking screw is at the center of the slot for timing adjust. And which I assume is the original location.
I installed the distributor with rotor and mark aligned.
The car won't start with locking screw at the center of slot. I have to turn the dist CCW to its max and the car is willing to start, but barely does.

Position B, distributor installed 1 notch to the right of position A.
Distributor installed with the rotor pointing at 2 o'clock ... With the mark on the distributor aligned to the rotor center, the slot was off of the locking screw.
In order to insert the locking screw, I had to rotate the distributor CCW (the mark on the distributor was to the left of rotor center, by 15 degrees approximately.)
This way the car started right away.
The timing slot was at the limit, I couldn't rotate the distributor CW any further. That's why I offset the distributor base, which is where the slot is. And this way it allowed more CW travel for timing.

I guess next I'll need to check timing chain wear.

Note: i didn't change the base, it's adjustable CW or CCW by loosening a couple of screws.


....Could this be the timing chain is off by a tooth??