rough idle?

Bluerocketsneeks · Post by **Bluerocketsneeks** » Sat Aug 25, 2007 5:23 pm

i have a 2000 neon.. and for some reason when the ac is on it idles really rough... it also does the same in reverse... how can i fix this?

hybrid-Srt2001 · Post by **hybrid-Srt2001** » Sat Aug 25, 2007 6:26 pm

mine has the same problem. it feels like the idle speed drops way low, the car shudders for a second then goes back to normal. one day it did it soo bad coming in my driveway that it almost completely died, and started knocking pretty bad. i'll let you know if i find anything.

Post by **occasional demons** » Sat Aug 25, 2007 7:09 pm

Our motors have very little torque @idle, therefore the a/c compressor takes most of it to function. I take it you have an atx. With an mtx you can get some serious shake with the a/c on and letting the clutch out when giving it little throttle or if you don;t quite catch that sweet spot the motor will come to a stop like someone shoved a sledge hammer through the crankcase. the shake is "normal". I've considered hooking a solenoid valve to the a/c coil and experimenting with an air bleed to raise the RPM's a little when the a/c is on, but basically I live with it. You could also tie the reverse switch output to the solenoid with a diode to keep the back-up lights from coming on every time the a/c clutch engages. getting the idle speed would be the trick though so you don't go flying backwards because this totally by passes the throttle. Thinking about it , probably better to live with the shakes in reverse!

Bluerocketsneeks · Post by **Bluerocketsneeks** » Sat Aug 25, 2007 7:09 pm

thanks... mine doesnt go back to normal though.. unless i turn the ac off or put it in park.... but when i rev the engine it's smooth... i dont get it

yeah reverse isnt a big deal at all... but i think a clip or something is loose on the dash so the rattles drives me crazy... but its normal?

hybrid-Srt2001 · Post by **hybrid-Srt2001** » Sat Aug 25, 2007 7:34 pm

my 95 had the same problem. then one day it bogged down and died at a stop light, and i smelled a burnt clutch smell. it turns out that my ac compressor clutch was going out and finally locked up, causing the motor to die.

Supermanneon · Post by **Supermanneon** » Sun Aug 26, 2007 1:01 am

2000 atx here and mine does it with or without the a/c. It will idle about 500? maybe 550? at stop lights but i just kick it to Neutral and back to drive and im good to go jumps up to normal and the shakes go away.

Post by **occasional demons** » Sun Aug 26, 2007 9:13 pm

Technically your IAC valve should keep your idle at the "target" RPM but unfortunately it doesn't always work. I think it's more of a pcm programming issue than anything else. I had a 94 Sundance Duster (atx) that would stall every time you let off the gas and hit the brakes too fast. That's with a V6-ofcourse it ever did it for the dealer.You could try removing it and cleaning it. If you do remove the whole TB and clean your butterfly as well. Don't use carb cleaner or any other kind of solvent though. Use castrol superclean / simple green or a similiar prouduct. Carb cleaner will destroy a plastic TB. Pobably won't help, but what do you have to lose?

Bluerocketsneeks · Post by **Bluerocketsneeks** » Sun Sep 02, 2007 11:41 pm

so the check engine light came on... i took it to autozone and they said the power steering presure switch needs to be replaced... apparently it supposed to keep the rpms up when you turn.... but since its bad the rpms are lower causing it to idle... but now i have to figure out what's rattleing in the front end