It has a 2.8 Lt engine I believe. While my husband is driving the car will just die. The battery is charged and as long as it has been doing this it's not the altenator because the battery would be dead by now. If we start the car before he leaves it dies before he can get out there to leave. We have done a full tune up, changing spark plugs, wires, and the fuel pump. We took it back to the mechanic right after we did that because instead of jerking like crazy now she was dieing intransit and when we would let her warm up. We then got the air sensor changed and she was fine for about a week and now she is doing this again. We have no idea what this is. We still have the catilac converter on it, I know that the mechanic was asking if we still had that on before the air sensor was fixed I didn't know if you needed to know that. Now when it dies it will not restart for a long time. If we let it sit about two hours or so, it will start right back up and we won't have a problem for the rest of the day normally.
When it refuses to restart, have a helper crank it while you visually check for spark at the plugs. If you have spark everywhere, use a gage and check fuel pressure. If idle issue, clean the throttle body and idle air system. If it dies at highway speed, check for rpm signal, comes from crank sensor. An intermittent rpm signal will drive you crazy. Any applicable mil codes. You can check those codes, yourself. You use a jumper wire between the A & B terminals at the datalink connector, turn key just till dash lites come on, no further. The mil on the dash starts flashing, you count the flashes to get the codes. Your looking for two digit codes. Let us know what you find.