I have a 1998 C70 and have had it for about two years. Recently I have had problems with my car stalling and the engine dying on my when the car is on (The engine quits and all the dash lights come on) it happens infrequently and there is no pattern to it. It has happened when the car is running but in park, while I was driving at low speeds, and once when I was at 50 mph. I drift off to the side of the road put the car in park and turn off the car. It usually re-starts with no problem. I put a used but seemingly functional fuel pump relay in (used) and that did not fix the problem. Also sometimes when I am driving my car will jerk and shift VERY rough but this too is infrequent.
My second issue is that sometimes I will go to start my car after a few hours of sitting, or overnight, and the it has trouble turning over... as if something is draining the battery but I can't figure out what it would be. The battery and the alternator have been tested and are fine. I'm not sure if these problems are related or not.
PLEASE HELP!!!

 

Sounds like fuel!! First change fuel filter.(Auto zone) if that's not the case
Possible fuel pump! Get someone to turn on the car to position 2 and listen for the FP!! no whine? FP...whine.. Check FUEL pressure. Its unde the hood should have a blue cap on it(I think) get a pressure Gage have person turn key to position 2 and notate psi. Before or after Find what it should be on!! Search here for fuel pressure someone has had same issue!! Good luck!!

 

Common problem for fuel pumps and fuel relays. Check the pressure and you can listen for the pump.

 

A bad MAF can do the same thing.