2004 Classic engine doesn't slow all the way down

I may be going nuts, again, but it seems like my 2004 Classic doesn't slow down like I think it should when I take my foot off of the accelerator. I notice it when I have run the car up to 40-50 MPH and then take my foot off the accelerator, I may have been reading 2,000 RPM at 50, and it will slow down some but it seems like the car wants to keep going faster and the RPM might slow to 1,000-1,100 range but not below, and the car might want to keep going 25MPH and does not seem to be slowing from that point. If I use my brakes it will slow down and the RPMs will start to drop, but I can have my foot off of the accelerator without braking and it will continue @ the 1,000 RPM for what I think is too long. shouldn't I sense and see the engine and speed of the car slowing? I have seen a drop in my MPG and am wondering if this isn't a factor especially in city type driving.

I have installed a new IACR, and that did not take care of the problem. ( I was trying to clean the old one and it broke) I cleaned the throttle position sensor and the throttle body twice. Is there another control/sensor that would make the engine continue to run faster than normal, maybe something with the Air Conditioning being engaged. Or is there some type of cutout switch that may not be working properly. Any ideas and suggestions appreciated.



Spit

probably the IAC

Look for air leaks in the intake, TB, PCV, and EGR systems.

If idle speed is normal, it's probably a bad sprag in the transmission. In other words, your coasting like in neutral.

The easy way to check that is to drop it into neutral.

thanks for the replies. I am not getting any CEL lights or any OBDII codes. would I get code if the EGR or throttle body was bad or leaking?

Also is there an actual PCV valve on this 2.2 ecotech? I have seen the hose on top of the engine is the valve at one end or another?


It seems like when I shift into neutral that the engine and the car slow faster than if I just remove my foot from the accelerator What is that indicating? I am getting aprox 24mpg in mixed highway city driving. Seems like I used to get closer to 28.

thanks

chuck

One more question:

I have never serviced the transmission on this car. I assume it would be a good thing for me to do a filter and fluid change... comments? This is a car that does not have a dipstick for trans fluid. I have changed fluid and filter on 1996 Lumina 3.1 and a 97 Blazer 4.3 and I assume that the transmissions would be similar and it would be the same process of dropping the pan etc.

Can anyone walk me through the fill and check level process on this car? I believe that I have to get it up level... at least for a proper re-fill. So all 4 wheels have to be off of the ground or I drain it with just the 2 fronts up, drop it an fill it. If I can make sure I have a proper refill level without getting underneath the car... (is that possible?) I would assume I can use a long funnel, and I can measure how much fluid came out as a minimum starting point for the fill. How do I best measure how full it is etc. with out a dipstick.
Any thoughts appreciated

Spit

Start the engine and allow the engine to idle until the transmission fluid temperature has reached the value specified. Depress the brake pedal and move the shift lever through the gear ranges, pausing a few seconds in each range. Return the shift lever to the PARK range. Raise the vehicle on a hoist. The vehicle must be level, with the engine running and the shift lever in the PARK range. CautionThe engine must be running when the transmission fluid fill plug is removed, or excessive fluid loss will occur. Transmission fluid may be hot. Since the actual fluid level is unknown, stand clear when removing the fill plug. Have a container ready to capture any lost fluid. Do not turn the engine off with the fill plug removed, as you can be injured by hot transmission fluid being expelled out of the oil fill opening.
Remove the transmission plug.
Important
Transmission fluid (At least 104°F) 5-10 minutes at idle will give correct temp.
Does the fluid have a burnt odor or a dark brown color?Check the fluid level. The fluid level should be even with the bottom of the threaded plug hole.Is the fluid level low?
Add DEXRON® VI or III if that what it came with from factory, automatic transmission fluid in increments of 0.5L until the fluid drains from the plug hole.
Install plug before stopping engine or fluid will spill out of plug hole.
Pan drop and filter change 7 qts
Check plug is just to the right of the passenger side axle housing , 11 mm plug, can't miss it, only one there.
Hoist is optional, just needs to be level and plug accessible. I found 3 inches of wood pieces at all 4 wheels will give checking clearance. I made 4, 3 inch wood ramps.

SLS,

Thanks for the info. The only way I ever did a pan and filter wato warm up the transmission shifting thru the gears, shut the car off and drop the pan and change the filter. So what you've written here is blowing my mind a little.

1. Are there 2 plugs you are referring to, i.e. a Fill plug and a Drain plug? This is a 2.2 ecotech with an automatic trans. and for some reason I was thinking that the fill plug was on the drivers side sort of below the power steering pump, but you mention the passenger side for the plug. Can you confirm the plug location(s)

2. Do I need to be sure to shut the engine off within a certain amount of time after the last of the fluid drains? sounds like I need to get the fill plug back in place 1st and then shut it off? so it doesn't spit/spill hot fluid.

3. I do refill the trans with the engine shut off? and then run and shift thru gears, and re-check level and add more fluid as needed.

Thanks for your help

Spit

Check plug is where I said. Drain with engine off.
Running is just for level check.
Fill is plastic cap under hood.
Always drain mine cold.

I think I saw the check level plug in a Youtube video..Now I am clear 2 plugs a fill and a check level.
Thanks again

Spit

http://www.chevymalibuforum.com/forums/showthread.php?t=62170 Here's a link, I just went through something similar with my 2003 Malibu 3.1L.