How it goes
 

Buy a timing cover seal and a camshaft seal with the intent of doing your front timing cover. Take off the distributor cap, and you realize that your cap and rotor are fried. Take off the rotor adapter and you destroy it along with the back cover to the distributor cap. Bang out the old camshaft seal and you realize the dealer gave you the seal for the crankshaft.

And that's how a $25 job turns into a $250 job.

Oops. Just snapped an old brittle vacuum line......

Sounds like you have the same luck as me and it ain't the good kind. How was your car running before all that? Mine (88 300SE) is getting to be hard to start at times. Not great fuel mileage either.

She was running pretty good, with a very slight miss at idle. Looking at the rotor, which had a fissure half way down the arm, and had a top electrode which was black and the texture of sandpaper, I'm surprised it ran at all. The cap had carboned through the coil input all the way around! How was this thing running?

The PO told me he just replaced it when I bought the car less than a year ago. I did discover he had put PLATINUM plugs in it, which could explain the burned up rotor and cap.

My MPG was around 17.5, but I drive heavy footed. I have been noticing soot buildup in my tailpipe, so it's running rich. I have a nice new 02 sensor which is going to go in once the cap and rotor situation is fixed.

As far as your hard starting, does it always do it or just when hot/cold? There are several things you can check. Be more specific with how and when it acts up.

My car seems to start easier when the outside temps are really cool or cold. Harder in warm weather, initially but seems to do better after engine is normal op temp.