So I've got two really annoying things happening with my car.
When I start my car it stays at 1500 RPMs until fully warm. Usually 5-8 minutes. Something's broken because today it was 65 degrees, but my car acts like it's in the 20's. I wanted to know if this happens with anyone else and what they did to fix it. This isn't normal right?
If I'm cruising in the higher gears, but have to come to a sudden stop the car's RPMs will drop to an almost stall out low. I usually put the car into neutral when this happens. I notice it mostly with 5th gear. Anyone else notice this.
If there's a way to fix this please let me know.
I have no CEL
It's actually pretty easy to take off... 2 12mm bolts, I believe. One of them is a bit awkward (if I remember right), but the IACV itself is easy to get to. Cleaning mine solved some idle issues I was having.
Cleaning the IACV will help. I had two clean ones, one from the car and one from a parts car. Both looked just ducky inside after cleaning. The original makes it idle well. (all things considered) The other one worked, but was much flakyier. It surged up and down on occasion, etc.
Either way, 1500 rpms on start up isn't that bad. Mine idles at 1300 until it is HOT. Then it goes down to my personal setting of 450rpms (which does make it shaky!)
ANY accessory raises the idle. Even compononents that aren't installed anymore like A/C. Turn the switch and the idle changes. One click on the heater, lights, brakes, anything. These cars are touchy.
I cleaned the IACV about a month ago. It liked being dirty because that's when I started to have the problems. I've cleaned it about 3 times now. I thought maybe I broke it when cleaning it. I used starting fluid the first time, and brake cleaner for the 2nd and 3rd. I even switched out the IACV with another one. Still have the same problem though. I figured the odds of them both being bad were kind of slim, but who knows.
Read through all of it. You'll be surprised at how in depth it is.
It talks about how to test it; 11.5 ohms unplugged, no continuity between the case and pins, etc.
I've cleaned mine and the entire throttle body probably 10 times. Tonight, for grins, I pulled both assemblies again. This time I backed out and cleaned the base idle screw. Come to find out, some prior owner had used what looks just like "Pipe-Dope" to seal the screw in. It has a gasket, so there's no need for this unless you have to set the idle really high (many revolutions out) to compensate for some other problem (like clogged egr ports, dirty throttle body, etc).
I cleaned the screw threads, the seat, and the "needle" part of the screw itself.
MAJOR idle difference this time. I had to warm it up and re-set base idle after pulling the back up fuse for a minute. Now it idles at 1250ish when cold but not until completely hot, it begins to idle down slowly before the needle reaches hot. It also does surge in neutral anymore (it was very slight before +or-100rpms).
Goes to show, you really have to clean every nook and cranny with q-tips and throttle body cleaner. I also dialectric greased all connectors after using qd electronics cleaner on them. This may have also made a difference.
Did you ever try cleaning your EGR ports and valve?
Did you spray all components afterward with the engine idling to check for vacuum leaks? I always spray everything with ether or cleaner and listen for subtle to drastic changes in idle.
Get back to us about your testing/cleaning/etc.