Timing Woes

[ricoled]

I can't get to read my timing marker properly. I tried to use a mirror to view the crank pulley's reflection, but it was impossible to do alone. Does anyone know of any tricks out there in setting the timing, short of having to remove the hood/bonnet in order to see the marker?  I wish the hood could pull vertically, just like the later model MBs...

Also, does turning the distributor counter-clockwise (against rotation of the rotor) advance or retard timing?? I might do a static timing instead..  Thanks

[Malc]

If you turn the distributor in the opposite direction of the rotation of the rotor arm then you are "advancing" the ignition ie making it fire earlier and earlier in the compression stroke. retarding is the other way and you can retard it so far that it will fire after top dead centre.
One trick that works is to make sure that the points gap is correct then start the car leaving the distributor loose, slowly turn it either way until it is running smoothly, you may have to twiddle the idle speed to keep it down. Then take it for a run up the road when warm in a high gear at low speed, if the engine pinks (pinging - USA speak) then you need to jump out and retard the ignition a little bit then repeat the process until there is no more pinking. I did this the other day for my old BMW and ended up about 5 degrees retarded from the factory marks because the head has been skimmed and we now have to use unleaded fuel.
If you get it right then the car will run fine, if too far advanced you could put a hole in the pistons due to the pinking (Pre Ignition) or if too far retarded power is down and the engine will tend to overheat.
Hope this helps
Malc
Scotland

[Naj ✝︎]

Hi, Martin,
It helps to clean and mark the pointer and the degree markings on the crank damper with white or yellow paint. If you have a good strobe, you will be able to see the marks lying with your belly on the left wing and feet off the ground, strobe held just above rad/fan.
Personally, I take the distributor off the engine and set the points where I can see what I'm doing.
Hope this helps.
naj

'Kloines Scheisserle'
65 230SL
68 280SL

[bayleif]

I have found it helpful to highlight the timing mark on the crank pully using my wife's white nail polish. The timing marks are accessible from underneath the car. I have highlighted a couple of them so that I can check timing at several different rpms. Then, wearing a glove on my right hand and holding the light in my left, I put my right hand on the oil fill cap and lean forward as far as I can. Then, moving my head to adjust the focal lenght of my 50+ year old eyes, I can usually see the timing mark pretty clearly.
The nail polish seems to hold up pretty well, but I think I'm going to remove the highlights, highlight only the 0 deg mark and then buy a more sophisticated timing light that lets me "dial in" the setting that I want.


Chuck Bartlett
1969 Signal Red 4 Speed

[ja17]

Hello Martin,
Everyone should be certain to push downward on the distributor before locking it down. A small drive spring between the distributor and drive gear tends to push the distributor upward when it is loosened for timing adjustment. If it is allowed to move upward enough the distributor will disengage and the engine will loose timing all together.

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If you have a weak timing light, total darkness helps a lot when timing. Try doing it at night or turn off the lights.

Joe Alexander
Blacklick, Ohio

[ricoled]

Thank you everyone for all your excellent advice!  My wife suggests I suspend myself from the ceiling using my hardtop hoist, but I'm afraid of damaging the car if I fall on it.    

The 'dial-in' timing light is my next step.  In the meantime,  I followed Malc's advice and not only gained lots of low end torque but also cured my overheating problem.  However, I now cannot rev above 4000 - I hit a 'rev-wall'.  Breaker gap is at 0.4mm.  Should I retard - or perhaps the IP isn't giving enough gas?  

Cheers! Martin

'68 280SL
'82 240D
'90 260E

[Malc]

Martin,
If you car revs above 4000 when sitting in neutral in the drive this would suggest a fuelling problem. When the car is under load, ie on the road the system is not getting enough petrol. However below are some guesses to point you hopefully in the right direction.
Finally this "rev limit" sudden and there or "stuttery"? the latter may suggest an ignition/electrical problem.

Check all the silly things first....
no kinked hoses or leaks
petrol (gas) tank cap venting properly??
Fuel pump delivering fuel at a high enough rate?
No blocked fuel or air filters
fuel return line ok
Somebody may know... is there a small mesh filter in the pump body somewhere - if so is it clean?
All the throttle body/accelerator links ok?
Is the throttle butterfly opening all the way ie syncronised??
Fuel pressure correct (worn pump, dirt etc etc)
Pump timing right?

(Note I actually haven't got my car from the USA yet, but I suspect the fuel system is like my 74 BMW 2002 Tii with it's mechanical injection system which must be timed to the engine and all the links set correctly)

The only other thing I can think of is if you have some air leaks somewhere on the inlet manifold somewhere which might make your car run very weak, make sure that any hoses that attach to it are attached!! and are not cracked or split.
Check the colour of the spark plugs:
 - black too rich
 - light brown/sand colour ok
 - white or "glazed" too weak
however only do this after running the car for a few miles when it is warmed up
Retarding the ignition won't make any difference the only problems in this area could be points bounce. This is if the "spring" to close them isn't very good, rare
The condensor is failing
the coil is beginning to go or the low tension side is wired the wrong way round
Does you rotor arm have a spring loaded rev limiter?? if so it could be cutting in early
Oh dear Sorry I went on a bit
Cheers
Malc
Scotland