Try plugging the vacuum brake booster. Also check the HVAC hoses inside the car. A hose may have come off or a bad vacuum motor.

 

^ + 1, I like these ideas too!!!!!

 

yes i removed the pcv, cleaned it, the pin inside is free to move (it rattles) i used a mirror and look all around at the hoses and the rubber boot the pcv goes into looks and feels good and snugg. It seem the motor runs fine sometimes until it warms up and sometimes after it warm it idles down normally at a stop so if i have a vac leak i would think it would be consistant not intermitent. Im going to try a smoke test today. One other thing to say the motor has 245,000 miles on it and on very rare ocation there will be a single cylinder missfire but very rare.

 

good point, i just remembered that under acceleration the heat/ac vent doors change from dash vent to upper windshild vent then back again when i let off the gas.

 

Good that the PCV valve is clean & moves freely, But that doesn't mean its ok, as if it has lots of mileage on it & its seat is worn, or spring is weak, it'll loose its unmetered but calculated for, calibrated leak rate. So, when last was it replaced????

The blend door moving with a change in throttle is a good clue.

 

its the original pcv valve

 

OK, so with 245K miles, it's already lived about 2.45 lifetimes, so replace that puppy while your at it, as its Way past due!!!!

 

yes your right will do that today.

 

There is a vacuum tank in the system that keeps that from happening. That might be the source of your leak. Check for a broken or disconnected line. If the lines are ok check the tank to see if it holds vacuum.

 

^+1 on checking the underhood vacuum reservoir & its vacuum lines for leaks. The Heater/AC is designed to fail in the Defrost mode, so your probably hearing the blend door opening & closing, when engine vacuum drops & the reservoir can't make up the
difference. A leak of this type will affect fuel trim & give the type fuel trim clue you have.

When you find & fix the problem, disconnect the battery B- cable for 15 min or so, or leave a door open or light on, to more quickly wipe the KAM & its corrupt fuel trim tables.
Then perform the cold & warm idle relearn strategy & drive it so the computer can begin to rebuild new fuel trim tables.

 

You can do a quick short cut. Find the engine source for hvac vacuum, cap it off at the engine and run your test again.

 

Still cant find any vac leak, put in new pcv valve. The speed up idle at a stop problem is intermitent some days i can drive 50 miles before it acts up, so it would seam that there was a vac leak it would be consistant. so fare ive replaced the pcv, air control value, upstreem 02, air cleaner, and cleaned the maf. now im thinking to go to the junk yard and look for a used maf sencer to try out.

 

When it does this, is the AC on????

 

no, the ac if off. I wouldnt mind buying a new maf sencer but there very pricey, in part because it looks like the sencer comes as a part of the aluminum howsing and you cant buy just the sencer

 

You can connect your "mighty vac" or the like tester that has a vacuum gauge, to the vacuum line that feeds the cabin heater/ac control panel & vacuum motors & pump up 25" of vacuum & see if the system will atain & hold a good vacuum, without leaking off & that would tell you if you have any potential suspects with the heater/ac control system. Same for the under hood vacuum reservoir canister, & EGR system, to see if they have vacuum leaks.

When your coming to a stop & it acts out, don't forget the EGR system comes into play & its vacuum sensed by the DPFE sensor via a rubber vacuum line at the intake manafold side of the differential feedback orifice tube port vacuum line connection, below the EGR valve, where it gets plenty hot & is prone to dryrot/cracking.

The EGR valve is vacuum controlled by its vacuum switching valve, so the EGR system vacuum control & sensing circuit lines & their fittings belong on your suspect list.

Lastly the vapor recovery system uses engine vacuum to purge the vapor recovery canister, so you could disconnect & check its intake manafold vacuum line to purge valve, to see if its holding vacuum.

If the PCV valve was due for scheduled maintenance replacement, or had never been changed, it was a good idea to replace it imo. Was its rubber connecting hose/elbo in good shape & tight fitting????

OK, so when it acts out the AC has been off. I was thinking maybe Murphys Law was messing with you & you had more than one problem, mucking up your trouble shoot.

Kinda sounds like you have a small subtle intermittent vacuum leak somewhere, thats prone to act out when coming to a stop, so keep in mind things that are in, or come into play when stopping.
More vacuum leak thoughts for consideration, keep us posted on your trouble shoot.