Humidity-Rain problems

[Hunter-AZ]

Ok, so I was living in AZ, hot and dry and am now in the tropics. I have an 86 runner, 22re recently rebuilt motor. When we would get the occasional rain in Arizona the truck just doesn't run well. Missing, chugging, smoking etc. A day or two after the rain all is well. So there I lived with it. Here it is unbearable, every time it rains it's a no go on the running. All the normal suspects are accounted for, cap, rotor, plugs, wires, connections etc. Water is not getting on the motor, so it must ambient humidity. Takes about 1 1/2 to 2 days after the rain to right itself. The TPS has been replaced with a genuine Toyota replacement and the O2 sensor with Nippon Denso. Someone mentioned and I have thought it must be a "sensor" problem, but what, where and how to fix it. Throw some ideas at me and maybe I haven't thought of it yet. Thanks in advance.

[stump runner]

don't know but if you figure it out i need to know. occasionaly when roads are damp, but motor does not need to be wet, my truck will idle/ accelerate perfectly but shut off at around 1700 rpm and come back at 1300. i've posted on this before but no answers. i've tried hosing the engine down to find the problem but it runs fine. i did figure out that there is spark so i think fuel delivery related. also cuts out at lower rpm with brake lights on. baffle:spanka:d.

[Hunter-AZ]

Just to follow up on this. I finally found a diagnostic mechanic that was worth a crap. After years with this problem he had it solved in an hour. There is a leak some where in the fire wall and a small amount of water was entering the passenger side kick plate. Some of that water was making it's way into the ECU. Upon opening the box it was clear there were water marks on the board as well as fair amount of corrosion. Now, here's the good part, I live in southern Mexico. Here labor is cheap, so a tech cleaned and re soldered the board for 40 dollars US and the mechanic charged me another 30. I have spent hours and hours and hundreds of dollars trying to track this down, changing this and that, adjusting, waiting for rain to duplicate the problem... So end solution was to seal the ECU with gray silicone, put some plastic in and voila, several downpours later and all is well.:redspotda

[stump runner]

i actually have opened the ecu box but there is no sign of moisture ever having been there. i haven't had any trouble lately, which sure makes it hard to diagnose. the best i can think is a cracked sensor or circuit board or chip or ???. glad you've gotten yours fixed though. if mine does it again i'll remember the computer and see if it has any water. may look for a computer on craig's list. seems like the most likely culprit at this point.

thanks for the advice.

[Hunter-AZ]

I would recommend checking the TPS first, I had a cracked board in that and it caused issues similar to what you are saying.