having a problem with my wife's "99" Sebring JXi convertible. The engine won't idle down to it's normal range ( vehicle has a 163,000 miles) . Engine ( 2.5 V-6 ) usually idles around 900-1000 rpm when fully warmed up, but recently will only idle at 1200-1400 rpm range. When you start it cold, the rpm will go shooting up to about 2200 for a second or two and slowly drop to the 1200-1400 range, but will drop no further regardless of engine temp. Wife ,who drives it most of the time, said that she first noticed it in traffic a few days ago and nothing else seemed abnormal. She said also that the service engine light came on when it started idling high. She took it to a mechanic friend of her's who reset the light ,but couldn't get the car to idle down. I looked for clues in the Hayne's manual , but so far haven't found anything vaguely similar to the problem that I have. Any suggestions on what to look for and how to test it ? Thanks.

Ted

 

this could be due to fuel injection problems or timing. its either running rich or the timing is advanced too far. you might also want to check any sensors or valves relating to idle air

 

I would probably have to rule out timing or too much fuel. I drove it about 25 miles round trip last night and run perfectly with the exception of high idle. Will do some investigating on sensors related to idle control.

Ted

 

Most probably, it's a vacuum leak somewhere. Take a piece of tubing and put one end near your ear and move the other end over all the hoses and connections of the intake manifold. Follow vacuum hoses their entire length and check the things they are connected to, like the power brake reservoir. If you hear a hiss where there shouldn't be one, that is the leak. A hose could have fallen off or just dried up and broke. Check the EGR system, the PCV system and (I think on that car) the heater controls which may be vacuum powered.