I have a 98 se auto and the idle jumps up and down about 50-100rpm. Its nothing major but its very annoying. I changed the fuel filter, pcv valve, and clean the tb twice. I checked for any vacuum leaks but couldnt find anything. There is also a whining sound when i accelerate. Not sure what it is but i sounds like its coming from the top of the intake. Pretty sure its not the belts. what could it be

 

is the car sorta jumpy when u are coming to a stop and going from a stop? cause my max did and i had to replace a few of the fuel injectors

 

Yeah, if your at a light and take your foot off the brake it feels like someone is jumping up and down in your back seat. By the way idle in park it 900rpm and in drive its between 550-600rpm

 

yeah that is what i had happen. It cost something over a hundred to get a few of the fuel injectors replaced...it was pretty bad before i got it fixed. sometimes it felt like it was gonna die because it was jumping so much. Right before i got it fixed it smelled horrible because it wasn't getting enough gas...probably should have fixed it before it got that bad...

 

I think the reason that It's higher RPMs at Park is because i automatically compresses the break, using the engine to do so...meaning it needs more power , hence higher RPMs...And when in Drive, you are pushing the brake, so It's not necessary...

Or am I talking out my butt?

 

Not true. But that's alright. In park, the transmission engages the parking pawl which is a sort of metal clutch or brake within the transmission. This prevents the car from moving in Park if you try to push it. What actually prevents the car from moving when the engine is still on (in Park) is that no drive gear is engaged.

The idle speed is controlled by the ECU.

 

At least someone caught me.