A problem I'm having.....Sometimes my car's RPMs would drop while on the open highway, then jump back up again to normal. No engine lights. Just 2300 (or so) dropping to 1300 (or so). Then back. The car also tends to stall at red lights unless I give it a little gas. FUN! I had the throttle position sensor and the idle air control replaced but that didn't seem to do the trick. (And other mechanics I've called seem to think that was what needed to be changed.) Look, I'm dumb about cars. I'm smart enough to know I have to bite the bullet and get a new car. My vehicle is a 1998 Chrysler (ugh) Sebring with 96K on it. Hell, as far as I know, the fuel injection system could be contaminated. I don't want to put more money into this car but if anyone has any ideas as to WTF it could be....?
Start with the smallest possible problem, and work your way up. 1) Check your battery terminals 2) Check all your fuses, you may have blown a sensor fuse. 3) When you are driving, and just when your RPM's drop, immediatley turn off the AC, if the idle rises, then it might be a air filter/intake problem. These are the most common problems I know of, so start little, and work your way up.
The RPM will jump when you kill the A/C even if everything is running well. When the compressor clutch engages, it leeches HP from the enginel dropping the RPM's. When you kill the A/C, RPM will jump a bit.
and also, if a sensor fuse had blown, it would trigger a check engine light...which he said has not happened. Two things. check air intake connections and make sure they are tight check the air filter if fuel filter has never been changed.....replace it it is unlikely to be a sensor problem if you dont have a check engine light lit possible, but unlikely.
