Driving In The Rain

Every time I drive in the rain my car seems to not accelerate. I will be accelerating and it will just not go. I will have the petal to the floor and it stays at about 2000 rpm's and usually stays at about 25 mph. I have to let off the gas and then floor it a couple of times for it to finally keep accelerating. Then it will seem like its backfirering. It seems to stumble. Its hard to describe. It only happens when it rains or if i hit a puddle. I have checked the distributor cap and nothing seems to be cracked or loose. The wires and spark plugs were just replaced a couple of months ago. Anyone know whats wrong. Any help is greatly appreciated. OH and its a 95 4-runner 3.0 EFI V6 4X4

Usually when damp conditions create problems it is the wires. I would say it is secondary ignition. Plugs, wires, distributor.

It only happens when it rains or if I hit a puddle. I have checked the distributor cap and nothing seems to be cracked or loose.
SO if it does it when you hit a puddle you can emulate a "controlled” wet down by wetting down half the engine compartment then drive it then narrow down the areas until you get closet to the area that causes your problem.

Of course you need to allow for drying time between tests.
Visual inspection of the wires and cap may not reveal a problem aggravated by moisture.

I had a very similiar problem, after changing cap, wires, plugs, fuel filter pretty much i could think of the problem turned out to be the computor(ecm). On my 1990 the ecm is mounted behind the passengers kick panel, I noticed the carpeting wet in that corner, I removed the panel and noticed the odd drip. The short of it is I moved the ecm to another location just to see if the problem stopped and it did. Oh ya there was a hole in floor and one up higher just below the wind shield.

Could also be one of the many sensors. Saw a similar thing happen on a Buick Grand National once.