Bogging down on acceleration

Got a weird problem I've never seen before. Wife complaining about the van having no power/acceleration. Started it up idles fine, go for a ride and really boggs down hard when accelerating, as soon as I let off the pedal it revs and takes off real nicely - like the vac caused by the closed throttle does something to cause it to rev right up. I can repeat this over and over, no CEL or other issues. Any thoughts? Problem showed up very suddenly, vans' been runnning fine till this.

I have had experiences similar to this ... no "power" and yet no codes. Fuel pressure issues I've found. (Does "filling up" seem to change it slightly?)

I would suspect: in-line fuel filters......fuel pump inlet screen (in tank)/debris in tank... fuel pressure regulator (model year dependent) .... etc, etc.

One fill up of dirty fuel can cause problems suddenly ... there is little defense!

I'll put a gauge on it later but I'm sure that's not it. This is something else. The sudden rev of the engine from open to closed throttle is very weird. I wish I could explain things better here.

......I'll put a gauge on it later but I'm sure that's not it. .....

The gauge will show you nothing unless you are able to rig it up so that you can watch it while driving about. Obviously you now have plenty of pressure when the engine is unloaded.

The question is ... does the pressure lower as you have poor engine performance?

The gauge will show you nothing unless you are able to rig it up so that you can watch it while driving about. Obviously you now have plenty of pressure when the engine is unloaded.

The question is ... does the pressure lower as you have poor engine performance?

Right, I get it. The wife also noticed white smoke from the exhaust while I was driving it around the block. I checked the coolant thinking head gasket but the level was fine. Could timing cause something like this??? Like maybe a camshaft position sensor?

If you suspect coolant leaks, be very cautious. Just a little coolant atop a piston can destroy an engine! Such a small amount would be hard to detect by watching the reservoir.

I always just leave the coolant reservoir cap a turn or so loose so that the coolant never gets to high pressure. This action lessens the risk of coolant finding its way into the engine. I recommend this to all ... but I think most believe I'm a bit unreasonable on this matter. ("How could Detroit be wrong!"). Leaving the cap loose will cost you a bit of coolant ... a cheap insurance, I say. Can't be done on old style systems that have a radiator cap.

If it were a crank or cam sensor ... you would expect a CEL. Does the lamp work?

yes, the lamp works.