Idle goes up and down, then stalls

[itsmytsi]

Hey all. I tried looking to see if this has been answered at all but didn't see it anywhere. Sorry for posting if I missed it. When I start my car to warm it up it will idle fine for a bit, then the idle starts to bounce up and down. It will continue this for a while and slowly idle itself down with each bounce a couple hundred rpm at a time. The idle seems to smooth out and then it will stall. If I try and regulate the rpms to keep it from going up and down it doesn't seem to help since it will do it again when I take my foot off the gas. Right after it stalls I can fire the car back up and it will be just like normal. I've had the car about 3 weeks and it wasn't doing it when I first got it. I live in Minnesota so I don't know if its cause of the cold or what. This is not only my first dsm (and I'm loving it so far) but my first car newer than 1974 so if its somehting simple I'm sorry. Thanks for the help!

 

[NA All The Way]

http://www.myzero.com/engine/surge.html[/URL] http://www.dsm.org/how-tos/tttt/tttt3.html
These shoould solve it for you. Basically the problem is caused by a disrupted fuel calculation. Which is caused by intake air entering the intake manifold after the mass air sensor.

 

[itsmytsi]

Thanks for the sites. I'm going to pull my car in my garage, crank the heater and get to work.

 

[NOSNUSE]

Try pulling the top vacuum line off of your EGR valve after the car warms up while the car is running and see if that works.

 

[wagman]

This happened to my car, try checking your timing, even if its off by like a half milimiter it might be able to do that, because the mixture is al messed up with the intake and exhaust valves.

 

[paranoidTSi]

Probably not in your case, but check intercooler hose connections as well as intake hoses, This happened to me when one of the hoses fell off, it'd idle to 2.5K, drop to 1K, go back up to 2.5K, go back to 1K..then just die.

 

[Revolution]

your idle motor is seased or seasing to function properly, granted that leaking air (blown or cracked line or pipe) could do that but why not look at the obvious befor jumping to conclusions.

When I first had those symptums I searched evreywhere to find a solution and all I found was d.i.y wich did'nt make any sense to me at all.
So after pondering for a week I went on a hunch that the idle motor (wich is responsible for the car and flapper to proper idle or open) could just be broken or could have come loose ,so I picked up a new one and guess what that was it problem gone . OH PS ... GET A CODE READER AND READ YOUR CARS CODES TO SEE IF THEIR IS ANY PROBLEMS , THAT WILL SAVE YOU TONS OF TIME.