High idle problem

[That1Guy]

For some reason my car is idling around to 1100-1200 RPM after warm up and i come to a complete stop.I notice this was a common problem for s13. I read around and i been finding different fix for this problem. something like adjusting the IAC or its bad engine ground. I notice this started happening to my car after a huge rain storm and i drove through a huge puddle of rain water. I have a 1990 240sx 5-speed . please help

[vocationalzero]

The rain puddle might of done something with a ground strap somewhere. Just crawl under and start looking, there is only 3 or 4 grounds on that car.

[That1Guy]

I also notice my alarm was losing ground as well before it the rain.It makes a click noise from the horn when it's not grounded but it was bolted to the frame. Maybe it something else?