When slowing to a stop, RPMs drop to 300 or below, then engine stalls out. Restarts OK but stalls out at next stop. Problem not observedso farin 3rd or L gear.

No error codes. Fuel system seems OK (50 psi). Clean throttle valve body.

98,500 miles.

Any ideas?

 

IAC valve.

it's located next to the throttle buttefly, and computer controls idle speed through it.
try to clean it and grease it (with WD40), reinstall and test drive it.
if you are not handy, leave it to the professional. try not to drop it when cleaning, it might die all together.

 

Thanks "I Wonder" ...been away a few days so I am just now getting back to you.

Looked in my shop manual and found an IAC Motor ...perhaps this is one and the same as the IAC Valvein your advice? I read the functional description and operation of the IAC motor and it looks like it could be the cause alright. The last line in the description says: "Deceleration die out is also prevented by increasing the airflow when the throttle is closed quickly after a driving (speed) condition." Described my problem exactly. I will let you know when I work this problem.

One other thing ...some time ago ... I did reset a check engine light with a DTC 401 EGR Flow Insufficient. Not enough time since resetting it for it to come back yet. Any chance this is connected to my stalling problem?

 

I don't think so.

stalling problem is very common and it's usually connected to IAC valve (or motor, becouse it's an electric motor).
AFAIK, EGR is tested only in specific driving conditions. you may have reseted CE light , but that does not mean that you have solved the problem. it may occur again, when conditions get right for testing.
also, problem with EGR can be similar to what you described, but it's not likely that the engine will die becouse of it.

 

EGR could cause this problem. EGR is only supposed to open on your vehicle while driving down the highway. so under throttle EGR opens. Now if EGR valve is sticking open and you come down to idle then the engine has a vaccumm leak and can have effects of poor idle or dying.

 

EGR flow should NOT be more than 10% of the total air entering the engine.
and in city driving, under small load, EGR valve is not opened at all.

that's why I said it's most likely about IAC and not EGR valve.

since he had 401 code, it may be that the engine is shutting down becouse of bad EGR, but my bet is still on IAC.

 

Just saying i've seen the EGR valve stick open when its not supposed to be.

 

Hey guys ...you were both right ...shop found a IAC Motor code that my handheld DTC didn't see and the egr valve was stuck open .... both replaced and running good...so far. Thanks for your help.

 

Glad to hear it.