they are in a bind, they bought the car from day one, it now has 325,000 miles on the original motor its a 4 cly not sure what litre, but when he comes home from work going on the freeway, his car will die on him about 5 times before he gets home, also sometimes the tach will rev to 6000 rpm when driving but the engine itself doesnt rev up, any help or ideas at where to look at first would help, had a resent tune up and ignitor installed, yeah i know it has huge milage thank you

 

if the tach is surging, check the alternator. I had that same problem and mine quit and I got stuck on the highway. After it went out, my ignition, headlight bulb, and possibly my speedo started to go bad

 

Coil possibly, most likely the alternator though.

 

he should load test system to determine where the fault is, it could be a bad battery but I would tend to agree with alt

 

My alternator was dying at 280K miles. I can see it in in the instrument lighting varying in intensity at night time (meaning it dims then brightens up). Headlights dim and get bright too. I did not get any engine cutting out or tach racing to 6k rpm though.
If it's ovecharging, it can do some damage on the engine electronic components.
Get it checked at any auto parts store asap.