If you are ever stuck, always check for a video from Robert:



Similar info here with more details:



Neil.

In addition to the above great resources, I'd add this write-up by cn90:
viewtopic.php?t=53722
It's helpful in this situation because it shows a couple of the different methods used to mark the gear:

The notch on the oil pump can be tricky to see sometimes, but it's there. Just shine a light at different angles and you'll see it.

What driveshaft wheel are you referring to? The only marks are on the cam sprockets/timing cover and the crank pulley/oil pump.

What color is the smoke...black or blue?

Move the coils around to see if the misfire codes change. Probably, you need two new ones

Is this engine coil on plug or distributor ignition system? For coil on plug type check coil grounds and swap around coils to find bad coil. For distributor type, check condition of coil wires and distributor cap.
volvolugnut

Compression test soon, if not next. Did this come on abruptly?

Sounds eerily similar to a problem I had with my 04 xc70 a few months ago. In my case it ended up being a burnt valve. If you going to be switching around the ignition modules anyway, your just 5 spark plug removals away from doing a compression test. You can get a usable on for about $25 on Amazon....

Coil packs on plugs did not come into use until 1999 models. Car will be a distributor with plug wires to the plugs. Check the plug condition. Also remove the distributor cap and check for damage/wear to distributor cap and rotor. Also look for oil in the base of the distributor. Turbo or NA? Check ...

What Neil said, start there, especially this:

scot850 wrote: ↑03 Jun 2021, 22:04 ... Also remove the distributor cap and check for damage/wear to distributor cap and rotor. Also look for oil in the base of the distributor.

but all of what Neil said.