Need help finding what's wrong.

[burtcheca]

I was going to go to town and after starting the truck I hit the road. After 300 or 400 yards into the dirt road the truck became sluggish to the point that accelerating, pressing the pedal down to the floor was doing nothing. The engine revved a little more but I was never able to pass 15 MPH. White smoke was coming out of the muffler and I never had that problem before.
Returned home driving very slow even that I was keeping the engine fast, never able to go from 2nd to 3rd, it was always in 2nd but weak. Parked the truck and changed the fuel filter thinking maybe it was clogged and the engine was not having enough fuel: it didn't change a thing.
Starts fine but is very weak, white smoke comes out of the muffler and is hesitating a little, not the even running of before. In idle works fine with the exception of a little white smoke.
Any ideas?

 

[icanfixall]

The white smoke sounds like too much fuel and its not getting burned off. Are you running any fuel additives. Has the rig sat for any long periods. How many miles are on the injection pump. Look at the drivers side of the injection pump. Open the throttle wide and watch to see if the advance plunger works.

 

[gandalf]

Another possibility would be a blown head gasket. All that white exhaust could be steam you're burning off from coolant leaking into the cylinders. Smell the exhaust, see what it smells like.

 

[burtcheca]

Smells like oil or unburned diesel, it's not steam.

 

[burtcheca]

I put a bottle of diesel clean with about 10 gallon of diesel in the tank. I filled up the new fuel filter with diesel clean straight from the bottle. The van was just for a couple of weeks parked there. The fuel injection pump has about 60K miles. Could it be the fuel pump?

 

[79jasper]

Is it a mechanical pump? Or has someone put a electric pump?

 

[burtcheca]

It's the factory mechanical pump. The injection pump is the factory pump too. The engine has only about 60K miles all of it.

 

[79jasper]

Well sometimes when the mechanical pumps fail, they'll leak fuel into the crankcase. So you may check your oil. But still go ahead and do a fuel pressure/volume check.