Hi, this is my first post here, I bought a 1991 YJ this july, it was in pretty bad shape (air filter soaked in oily goo, spark plugs with barely anything left, leaking fuel filter, broken/rusty rear shock mounts, VERY worn and rusty brakes, fluids missing all over +++).
I shopped parts for about $1400 including shipping to Norway, totalling about $1700 including Norwegian taxes delivered to my door.
I have changed oil, oil filter, air filter, spark plugs, spark plug wires, ignition coil, serpent belt, coolant. I have also cleaned the air intake, the IAC was covered in a hard, oily substance. I also cleaned the throttle body as it was full of the same substance as the IAC.
The engine is much easier to start now, and it idles stable at about 6-800 rpm's untill I start to drive. (Although it idled pretty stable before the IAC cleaning, amazingly. It's almost a wonder it even started before the overhaul, as the air filter seemed almost clogged).
The strange thing is, when I start to drive, then let of the throttle and press in the clutch, the idle rpm is about 1200 rpm UNTIL the vehicle is stopped. When the vehicle stops completely, the idle drops back to the normal 6-800 rpm. When I start driving again, and repeat, it does the same thing, it must stop completely for the idle to drop from 1200 to 6-800.
Is this normal?
I have searched all over to try and find a solution to this - maybe the O2 sensor could be the problem? I can't find any vacuum leaks, although I'm not a pro at cars, this is the first car I have ever been working on (and I love it).