Any idea why my truck is shutting down?

i have a 1998 dodge ram with 180.000 km,my problem is when I'm driveing on the street or hiway with out warning it just shut's down stall's out. I changed the fuel pump and did a compleate tune up on it but still have the same problem.when this happens I pull to the side of the road put it in park turn the key and it start's up rightaway put it in drive and away I go but the next day the same thing happens it just shut's down. any idea or sugesstion will be appricated. pat

It can be the electronic ignition.the pick up coil in the distributor.

I had the same problem only on my Ford truck. I ended up put a new distributor in and have had no problems since.

Another long shot is a burnt intake valve. this can because the same thing.

I could look at the distributor 1st.

If you have a numerical oil pressure gauge, I could make certain at cruising speed you have AT LEAST 30 psi oil pressure.
The other problem may be the fuel filter if it wasn't changed simultaneously as the fuel pump Have a shop test your fuel pressure regulator.

I have a '98 Town and Country that started giving my the same trouble. learned that it was a flawed Cam timing sensor.
I read that you replaced the fuel pump, did you also replace the fuel filter?

low battery maybe?

I had the same thing happen to a Chrysler Van a couple years ago. Turns out I had a bad seal on an axl and the transmission liquid leaked. When it had seriously low pressure the sensors told the computer and the computer killed the engine. The shop hooked it up to a diagnostic computer and told me it was the tranny, but it was not. Luckily the axl broke before I did the tranny work.

Basically, all you may be able to do is hook up the computer to a diagnostic to learn what kind of signals its been logging, then go through whatever system shows the trouble signal till you find what is causing it. Also it may just be a bad sensor someplace.

Impossible to say with the information provided. I could start by checking spark when the car wont start. It may be a cam/crank sensor issue or a coil issue

Does this issue usually happen in rainy or wet conditions?
That could point to a spark plug wire breaking down.

It could also be a fuel issue. If you have a fuel pressure gauge it could be a smart idea to check fuel pressure when it wont start.