I haven't driven my 95 LS for the past two days, and this morning, it started acting weird. As I was warming up the car and scraping the ice off my
winshield (it was around 10 degrees out), I noticed that about a minute after I started the ignition, the car started to automatically rev up the engine in
increments of 1-1.5 seconds on its own. When I shifted to D4 (I have an auto), it stopped revving. However, as I was driving towards school, it
intermittently started doing it again. At the first stop light I reached, with my brakes depressed, it kept revving the engine forcing me to creep up and I
had to engage the e-brake at every stop light and stop sign on the way to campus so that I don't hit anyone or anything.
This occurs whether I'm in park, reverse, neutral, d4, d3,d2, d1. While in drive, without putting my foot on the accelerrator, the engine will rev up to 2.5rpm to 20mph (should normally be at 1.5-2.0rpm at that speed) and stay steady at that speed for about 1-1.5 seconds, then drop to 0, then repeat the process. If I press the brakes while it's doing that, my whole car lunges
forward as if I slammed the brakes, then it'll rev itself up again. When I press on the gas while it's revving, the heat needle will go all the way to hot,
and come down only when I press the brake (remember, it's 10 degrees out). This only happened once while I was looking for a spot in the parking lot. Can anyone help me diagnose this problem???? Any help is GREATLY appreciated.

 

Did you check your coolant level? If I remember correctly the idle will fluctuate if the coolant is low.

 

next time put it in neutral at stoplights so you dont hit someone

 

it happens in neutral too...

 

low coolant or your vaccum line. check both.

 

if your coolant level is fine have a tech adjust the idle air control valve