Misfiring After Rain

When I leave my 2001 Tundra out during a hard rain and then start it, it runs very rough and seems like several or many cylinders are misfiring. So bad that when I attempt to drive it, it gets worst to the point of no acceleration and almost dying out. However, when I leave it for sit for a few days (no more rain) or drive it around the side streets it clears up. It does have some rust around the hood area. Anybody have any ideas? I’m going to change all the plugs and ignition coils and see if that works. Truck has 180,000 miles. Thanks! Garry

 

Well, sounds like an obvious electrical short issue. O2 sensors seems like a place to start as they are pretty exposed to road water...but could be a variety of things, coils, fuel pump...or ECU, Get out a hose, turn it on a little bit, and start wetting down likely looking places, starting from the bottom up for obvious reasons, until the problem happens, should be able to narrow it down pretty quickly that way.

 

Well, sounds like a case of water intrusion, or water vapor messing with things.

I'd be suspicious of the MAF, the O2s, and I'd also check your ECU to make sure you're not leaking water into it like this guy.

 

I'd also be interested if there's any codes set or pending.

 

I'd try a few of the things others have suggested before buying coils. If you do buy coils make sure and buy denso and not from scamazon either. Get them from a reputable place like Rockauto.