Starter problems after cylinderhead removal

[mulrik]

I just had the cylinder head off to replace the gasket and put everything back together, however now the car won't start. Before replacement the car started fine.

We forgot to note how much the cam was off when we took it apart. Now the camshaft is "behind" by ~12 degrees ATDC as measured on the crank. We couldn't get it right on time and in a post Joe Alexander wrote that it should never be early, but that it would be normal for it to be a little late. Is 12 degrees ATDC to much too late? or do I need a new Woodruf key??

We are also unsure about the timing between the crank and the injection pump. Is there anyway to chack this timing without removing the injection pump? And would you suspect the alignment between the crank and the injection pump to be altered by cylinder head removal and messing about with the chain from above?

Also it may be that I have set the injection pump with the cam and the crank 180 degrees wrong. Would that cause starting problems or just rough idling? The easy way to solve this problem would be to turn the ignition 180 degrees as well, don't you agree.

I appriciate any help I'm getting frustrated in ignorance here.

THANKS!!!
Ulrik



'67 250 SL Papyrus White 113043-10-000023

[ja17]

Hello Ulrik,


The injection timing cannot be easily checked. It is easy to get it 180 deg. off during head removal.

The engine will usually  start even with the injection pump 180 deg off. If the camshaft is hooked up 180 deg off the ignition timing will also be 180 deg off and the car will not start.

First sure you are getting fuel, the injector lines take a lot of cranking to refill with fuel after removal.

Do a static timing check, making sure spark is at # 1 cylinder on the compression stroke TDC (front camshaft lobes upward).

You can check basic injection timing by removing and fitting and valve from the injection pump and finding out which pump plungers are the up position.  
This can be a little complicated. Try the other checks first.

Your car should run fine even  at 12 deg. late on the valve timing. One chain link is 18 deg. so your chain position is most likely correct. A worn and stretched timing chain and cylinder head cutting will make your valve timing later.

I suspect cam timing and ignition timing off 180 deg. in your case. Your engine will not start in this situation. If you had your distributor out you may have repositioned it and now your cam and distributor are 180 deg out of time with the injection pump. The engine may start in this situation. Keep us informed.

Joe Alexander
Blacklick, Ohio

[mulrik]

Joe you must to be some kind of god!!!

We repositioned the camshaft to fit exactly with the crank. We set the static timing at 6 degrees BTDC. It turned out we did not shift the injection pump 180 degrees away from the ignition, so we didn't look into the injection pump is you suggested.

However, we did one thing more. The plug in the ignition coil was a little loose so we cured that, and even though we had checked for sparks at the plug, all these things together made the car start!!!!!

We were a little worried because a lot of smoke came out at the manifold:exhaust pipe connection, but that is down to a minimun by now.

I am so reliefed!!!

Thanks!!! again

'67 250 SL Papyrus White 113043-10-000023

[mulrik]

Oooops one more question. What is the correct static timing for a 250 SL.
Ulrik


'67 250 SL Papyrus White 113043-10-000023

[ja17]

Hello Ulrik,
The static timing is meant to be used as a temporary set-up to get a non runing engine in time after repairs or ignition work. 6-8 degrees BTDC should work fine.

The timing should be re-set at some point again after the engine is running. Setting the engine timing will tell you if the vacuume and centrifical mechanisms in the distributor are working properly. The vacuume cell on the distributor may fail as they get older or the centirifical flyweights or springs in the distributor may get stuck or break from corrosion.

On your engine smoke; engine oil can contaminate the exhaust system, after the engine is repaired it may take several runs to burm the oil out of the exhaust.

Happy motoring!



Joe Alexander
Blacklick, Ohio