distributor timing and position

[ericlee]

I have a 68 280sl with 051 distributor.  I have same problem as Joe had that distributor can not be rotated CCW anymore to get correct timing in this email below,

http://www.sl113.org/forums/index.php?topic=739.0

My distributor is at wrong position, vacuum cell is at 12 o’clock looking to front and condenser is at 6 o’clock.  Does the 051 distributor has the same design as the 042 with slotted gear and little spring, and can turn 40 deg on each tooth? Will the procedure to correct the position be the same per JA17’s procedure in the same email?

(2) I also have a problem with rotor position.  When #1 is at TDC, the distributor rotor does not point to the little notch on the distributor rim, but about 15 deg to the left(ahead), close to the tab on the rim.  See attached pic.  Can anyone please tell me how to correct the problem?

The car seems running OK, but idle at 15 BTDC at 1000 rpm.

Thanks a lot!

[w113dude]

check to see if the camshaft grove at TBC is right on,

[ctaylor738]

The notch is a rough reference point for installing the distributor and plug wires.  Once you have timed the ignition its relationship to the rotor will change. 

I believe the distributors are similar wrt the slotted gear.

But why do you want to go more ccw (advanced) if you are already at 15 btdc?

[ja17]

Looks like  your distributor is too far advanced to me.  Normally the advance cell is pointing between the 1:00 to 2:00 position. Start by static timing the distributor.  With engine at TDC #1 turn the ingintion on, (engine not running) , turn the distributor clockwise then back  counter-clockwise until the rotor points toward the slash.  During this move counter clockwise, the ignition points should spark. thisi would be a good starting point to lock down the dfistributor. Start the car and run the engine up to 3,000 rpms and set the timing by turning the distributor as needed. Re-check the idle rpms. If not up to specs find the problem. (retard vacuum cell, stuck advance, bad springs, worn bushings etc.) 

[ericlee]

Thank you all for your responses.   If I turn distributor CW, engine will stall.  Turn CCW makes it run better.  Is that due to distributor is one gear (40 deg) off on the slotted gear, and thus cause everything make no sense?  Should I first pull distributor out and rotate it to the correct position and then do static timing?  Do I have to make the clot line up with notch or it is OK not aligned?

Joe, I got this problem while I was trying to install Pertronix ignitor, so I do not have point now.  I used a test light to do static timing, but the engine will not start at distributor position per static timing, I have to turn it CCW quite bit to get engine started, so the vacuum cell endd up at 12 o'clock position.
Thanks again.

[ja17]

Hello Eric,

Try just loosening and lifting the distributor enough to  rotate the rotor clockwise enough so when you  seat it again it is advanced that 40 degrees more. Now set up the timing so it will run and see if the vac cell is in the right place.  Check your distributor number to make sure it has not been changed. to a different version.

[ericlee]

Hi, Joe,
My distributor is 051.  Do I just loosening, lifting and rotate the distributor or do I need to pull it out and use a sloted screwdriver to turn the slotted gear?
Thanks,
Eric

[ja17]

Hello Eric,

Sorry, thinking of a different model.  Yes, lift the distributor out noting the position of the rotor. Its best to set the engine up at Top Dead Center, compression stroke #1. So you do not get lost. Below the distributor you may find a spring, look for it, it should be there. You will see the gear and slot. Note the position of the slot. Pull the gear out and turn it clockwise  about 40 degrees and drop it back in. Now check to make sure it has moved from the original position noted. Install the spring and distributor. Make sure the slot in the gear and the cog in the distributor are matched up. They are not semetrical but are slightly off set. The slightly off-set slot and the slightly off-set cog must align. You can accidentally force them in and be off  180  degrees. Static set the ignition and check to see if your distributor has re-positioned.  The spring under the distributor will push the distributor up and dis-engage if you leave the distributor loose. Be sure to tighten it after timing is complete. 

[ericlee]

Hi, Joe,
I think I understand how to do it now.  but one more thing, how do I align the rotor slot to the notch on the distributor rim?  see the picture at beginning of this thread, they are off by about 15 deg now.
Thanks
Eric

[ja17]

Hello Eric,

When you change the position of the gear below, the rotor will also change position. When the rotor and distributorvacuume cell are oriented correctly, set up the static timing.