So I've got a vague problem I'm hoping for help with.

I have a 1984 Mercedes 300TD wagon with ~250k miles that runs really well and is overall in good shape. I change my fluids regularly and take care of it, but problems are inevitable.

When the car is cold, it starts every time with no problem. However, if I turn the car off and want to turn it back on with 15 minutes or so, it cranks but won't start. I usually have to crank about 4 times, waiting about 5-10 seconds between cranks, and then it'll catch. If I'm starting and stopping a lot, the engine sometimes loses power and I have to repeat the process.

Money's tight, and I don't mind getting my hands dirty, but do you have any advice as far as where to start troubleshooting this problem?

Thanks for the help.