My 87 4runner has a rough idle, kinda like a bad plug, and no power, like a filthy air filter and fuel filter when it is raining. I don't even have to drive it for these problems to start. If it is sitting out in the rain it has these problems when I start it, when the rain quits, by the next day everything is fine. The plugs, wires, rotor, and dist. cap, air and fuel filter, O2 sensor are new, and TPS 2 years old. Any ideas? TIA. Robert

I had a similar problem. Turned out, the igniter case was loose and letting water into the igniter, and causing it to short out. I sealed up the case and problem went away.

I found it by taking a water bottle and misting around the engine bay until the engine sputtered. Sprayed the igniter and found the culprit.

I'll try that, as soon as it quits raining, but what don't get is it will do it without driving in the rain. Thanks. I will try that and see what happens. robert

Same here. When it rained, I'd come out to the truck after work and it would take like 20 seconds of cranking until it finally started. Then after a hard rain I could not get it started at all.

And going through water crossings would stall the truck out. Pretty embarrassing when you got this built truck on 36's and you go through a little puddle halfway up to your tires and your truck stalls out on you. <img src="/forums/images/graemlins/frown.gif" alt="" />

How about this. When I turned my headlights while driving down the road today, the truck jumped, like I turned it off, turned the key on, and dumped the clutch to start it. Then when I cracked the rear window, it did the same thing. I'll have the alt. checked tomorrow as well. I am putting a transmission in Sat. so it might have to wait till Mon. Thanks again for you input. robert

Yea, check the voltage level of the alternator. Should put out 13.5 to 14.5.

I had a similar problem on both my 4Runners at different times. On one when I turned on lights or other electrical load it died/jumped less than a second like it died. I cleaned and retightened the battery ground terminal and it never has happened again. I removed the little plastic spacer in the ground lug so it could go tighter onto the battery terminal.

The other 4Runner would do the same thing whenever I hit a bump in the road. This was really annoying and unnerving. Turned out the EFI relay was loose in its plug and would bounce when I hit a bump causeing the EFI system to shutdown for a second. Then it would come back on when the relay reseated. I pushed the EFI relay in tight and problem solved for good.

good luck