I have a 97' chevy silverado 2500 deisel, It's started running real bad, it won't idle properly and it puts out a load of black smoke. If I try to drive it, it will cough and splutter and won't go over about 25mph. Every so often it will start revving up real hard on it's own. I'm on a budget and would like to fix it myself so if anyone has any ideas I would appreciate it.

Try reading through the FAQs here: http://www.dieselplace.com/forum/showthread.php?t=53309

Welcome to the forum PA Dan.................

Do the diagnostics, as suggested, also post any DTC's - your symptoms are classic DS4 Inj Pump failure, tho, so you might also post your original IP numbers, found on the Stanadyne tag on the rear side facing the intake manifold.

Will be a DS4-XXX-XXXX number - can see it with small mirror.

You should start checking around for a 5521 replacement.

Also post your mileage, as a new timing chainset is necessary over 100kmi.

If under 120kmi, the IP is still in warranty - info in FAQ's.

if the truck has less than 120K miles on it the ip is under warranty? even if the truck is 10 years old? what else is under warranty?

The Inj Pump.............

Special injection pump warranty good for 11 yrs

Ok, thanks for the help guys, I'll look into the inj pump, it has 205,000miles.
I haven't had that long, I got it from a guy I know so I can find out a bit about what it's had done in the past.

Take your VIN to the dealer for a database search on previous maint\repairs

Forum VIN check area can also get some info for you