How do you know when you are on the compression stroke?
 

According to the FSM, if you plan on adjusting your injection timing, it says to "Set crankshaft in direction of rotation to 24 deg. + 1 deg. before TDC in compression stroke of first cylinder."

Now, the crankshaft rotates twice for every camshaft rotation. So, if I rotate the crankshaft to 24deg. BTDC, how do I know if I'm on the compression stroke, or whether I still have one more rotation to go?

The compression stroke is after the intake valve closes on that cylinder

So does that mean I remove the valve cover, turn the crank to 24 deg. BTDC, then look if the cam lobe on the number 1 intake valve is pointing up? If not, rotate the crank one more time and then I should be good to go?

Basic 4 stroke theory review..

Intake stroke.... piston going down, intake valve open, exhaust closed
Compression stroke....piston coming up, both valves closed.
Power stroke.. piston going down, both valves closed
Exhaust stroke ... piston going up, intake valve closed, exhaust valve open.

There may be some overlap at the margins ... when the piston is at the top of its travel between the intake and exhaust... but diesels have about the least of that so that should not cause any confusion...

Follow up question:

The FSM says when checking injection timing via the begin of delivery method (flow pressure method) to "turn crankshaft in normal direction until crank angle is just short of start of delivery in compression stroke of first cylinder."

What does that mean in plain English?

You know you're on the compression stroke when she yells 'Yes!'

Scott - what engine are your working on?

My 240D - OM616.

If his answer to that changes the answers in this thread I am in big trouble...

Only if he said " a mazda rotary" or " a two stroke saab" ... :)

I know it's in the diesel discussion but I just had to ask. Cus if it was gas there is a real easy way.....

Scott, yes you are on track

Remove the glowplug and put your finger over the hole while you turn the engine.

If the start of delivery is 24 deg. BTDC (typical setting), they want you to set the engine at 25 BTDC before you start the procedure.

With the valve cover off, just look at the #1 valves. Either they are both partially open or they are both completely closed. When closed, the cam lobes are pointing up and away from the rocker arm.........might not be straight up but nowhere near the rocker arm.

Both lobes of #1 cyl should be visible if you remove the oil filler cap & look down at the cam. If straight up is 12 o'clock you should see both lobes above the 9 & 3 o'clock positions. This will be your compression stroke.