2005 S80 - Stalling at idle - no check engine codes

gvsu4msu · Post by **gvsu4msu** » 13 Mar 2018, 11:14

Having an issue that neither myself or my mechanic can seem to figure out why my 2005 S80 2.5T stalls when you come to a stop.

It runs fine as you are driving distances, but when you come to a stop at an intersection it stalls out. You can toss it into Neutral, and restart it. It will run fine until you stop again.

No check engine codes are tripping on this condition either.

For other issues we have already replaced the Fuel Pressure Sensor, MAP Sensor, Fuel Filter, and Fuel pump, and possibly other parts that don't come to mind at the moment.

At a loss. Anyone else have this experience or thoughts on what it can be?

Frustrated that we cannot get the computer to throw a code to diagnose, and it is not safe to drive if it is going to stall in the midst of driving it.

Thanks in advance,

hu5ker555 · Post by **hu5ker555** » 13 Mar 2018, 21:04

Have you cleaned up the throttle body?

gvsu4msu · Post by **gvsu4msu** » 13 Mar 2018, 21:15

yup, and replaced IAC as well.

Post by **mrbrian200** » 13 Mar 2018, 22:20

Please clarify, when you restart it it idles normal and seems fine in N or D. After getting up to speed it dies when you come to a stop.

Have you tried putting it neutral as you pass below 20mph while coming to a stop?
Considering what you have already done I might suspect a trans issue.
If the TCC isn't disengaging for some reason the engine will die as you come to a stop.
I have seen this once before. Granted it was on a 90s-something GM, a Beretta if I recall.

gvsu4msu · Post by **gvsu4msu** » 14 Mar 2018, 07:36

When it stalls out, I can put it in neutral and it will restart. I put it in drive and it will act fine. When I slow down and come to a stop again, it will stall out (or not - not every time which is the bugger).

per the post above, I have not tried slipping it into neutral while driving to see what it does. Can you tell me what the TCC is you abbreviated?

Post by **RickHaleParker** » 14 Mar 2018, 09:06

Check out the charging system and battery. The alternator could be loading the engine too much, causing the idle to drop too much. Incorrect voltages will confuse the control modules. Also check for excess drag on the A/C clutch.

gvsu4msu · Post by **gvsu4msu** » 14 Mar 2018, 09:19

Battery is new as of last year.

Post by **RickHaleParker** » 14 Mar 2018, 09:31

That was then, what is now? ... Shit happens.

atman100 · Post by **atman100** » 14 Mar 2018, 13:46

I had this same problem with the same year vehicle (155k miles) and I replaced the MAF Sensor, the 02 Sensor (forward) and that helped but it was the throttle body that needed cleaning. I posted my experience on here about a week ago. At higher speeds the throttle opens to let in air and there is no problem but at idle , the valve closes and the dirt in it blocks the fine slots that allow idle air to get by. Your spark plugs and O2 sensor likely have a black sooty fur on them. You may eventually get code 2188 Bank One Idle too rich

gvsu4msu · Post by **gvsu4msu** » 14 Mar 2018, 15:06

Thanks. I will relay this information.