Vehicle is having trouble starting, when I get it to start it runs fine for a while but eventally dies...?

The biggest problem on this vehicle (that will cause these symptoms) are the PCM (Powertrain Control Module) and the ignition coil. First, check the odometer (when the problem occurs) for the message "No Bus" in the odometer display.

It does Sound like Fuel.

It may be a Weak Fuel Pump

Especially if Run below 1/4 Tank Frequently.

Gas keeps the Fuel Pump Cool.

Fuel Filter is Part of Pump Assembly in Tank.

There is a Fitting on the Fuel Rail for Testing.

Connect Fuel Pressure Gauge and run Van.

Observe Fuel Pressure until Van Stalls.

If Pressure Drops Fuel Pump is Weak.

If Pressure Holds Check Spark.

Yes it can also be Bad Gas.

Especially Cheap Off-Brand Regular.

May have Water in Tank.

Techron and a Tank of Good Gas may Help

If Fuel Quality is an Issue.

To Check for Water take Fuel Sample.

Let Set in Covered Jar.

Look for "Bubbles" at Bottom of Jar.

This is Water...Water Heavier than Fuel.

Check Spark Plugs for Wetness.

Perhaps Coolant from a Head Gasket.

Would give White Smoke

Possibly Stall Engine.

Coolant Temperature will be Hot.

Coolant Level will be Low.

Replace fuel filter.

white smoke don,t sound good, maybe the head gasket !