hey guys i have a 90 4x4 with a 22re. It runs like a top most of the time, but when it rains or gets really humid it seams to loose some power. another thing that happens is from about 1/4 to 3/4 throttle there isn't much of a power difference but once past about 3/4 it gets a increase in power sort of like a 2 stroke bike would..... this only happens when it is really damp or raining. any of you guys ever have this problem and know what might be wrong?

 

First thing I would check or just do is to replace the cap,rotor and wires. Do yourself a favor and buy a toyota or quality cap and rotor. The other thing you can try is a water spray bottle, while it's running start spraying different areas but do this one by one because it might take a minute for the water to get to the problem. I had the same problem with mine slight rough idle then dead spot (falling on its face) then powerband kicks in.

 

around 7000 miles on new wires rotor and plugs cap looked great. The only thing I can notice is the dead spot. sitting there it idles smooth and sounds great.

 

Can't believe I might be able to help with something, I am no mechanic but I do drive a '94 pickup with the same water issue. Look for some wires that are connected with a rubber boot, near the radiator overflow. This boot can look tight but not quite be, which will allow a little moisture to get in there. When this happens, the truck idles fine but has no power until the water dries up.

I apologize for not being able to name the part more precisely, I'd post a pic but the truck is in the shop at the moment (subject for another post!). This may not resolve your problem, but it sure won't cost you more than a minute to find the boot and jam it together a little tighter just-in-case.