IPD sale XeMODeX - Experts in Volvo Electronics
Did you know? 🤔
Logged in users can get email notification of topic replies Log in or register (free).
Amazon Link Buy your stuff using this and it helps MVS!

850 stalls when slowing down to a light or in gear except when I disconnect the iac

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

mescalinedreamz
Posts: 3
Joined: Wed Nov 04, 2015 8:59 am
Year and Model: 850 t5 1997
Location: Wixom, michigan
Has thanked: 0
Been thanked: 0
mescalinedreamz

850 stalls when slowing down to a light or in gear except when I disconnect the iac

Post by mescalinedreamz » Sat Nov 02, 2019 7:24 pm

I installed a new idle air control valve hoping to fix it..both old valve and new check out fine. Anyways I can plug the idle air control valve in when the car is cold and it won't let me put it in reverse or drive without stalling..park and neutral I get a steady 1000 Rpms..when warm I can feather the gas and take off but not when cold. When slowing to a light I can stop and a second later the Rpms drop to zero.

Now with the idle air control valve disconnected it'll die from cold at idle in park or neutral until warmed up and then I can drive it normally but gas mileage suffers. So I usually warm it up with the iac plugged in and unplug it when warmed up..or else I keep the iac plugged in and throw it into neutral at every stoplight.

I'm thinking a sensor..maybe the temp sensor located under the thermostat..but not sure..gonna test it when cold and warm tomorrow. It's getting cold here in Ohio and it takes awhile to warm this thing up..thanks!



User avatar
RickHaleParker
Posts: 3253
Joined: Mon May 25, 2015 2:30 pm
Year and Model: See Signature below.
Location: Kansas
Has thanked: 3 times
Been thanked: 382 times
United States of America
RickHaleParker

Re: 850 stalls when slowing down to a light or in gear except when I disconnect the iac

Post by RickHaleParker » Sat Nov 02, 2019 9:53 pm

Leaks in the Air Intake.


Platform: P80 1998 C70, B5234T3, 16T, AW50-42, Bosch Motronic 4.4, Special Edition package, Plant: Uddevalla Sweden.

Platform: X40 (Nedcar) 2003 S40, B4204T3, 14T twin scroll AW55-50/51SN, Siemens EMS 2000. Plant: Born Netherlands.

Platform P2 2005 XC90 T6 Executive, B6294T, 4T65 AWD, Bosch Motronic 7.0,
Plant Torslanda Sweden.
----------------------------------------------------------------
1997 S90, B6304S, AW30-42, Bosch Motronic 4.4 - Sold

User avatar
misha
Posts: 4018
Joined: Sun Dec 07, 2008 4:09 pm
Year and Model: '97 850 2.5 20v
Location: Serbia
Has thanked: 36 times
Been thanked: 96 times
Serbia
misha

Re: 850 stalls when slowing down to a light or in gear except when I disconnect the iac

Post by misha » Sun Nov 03, 2019 4:59 am

+1.
If it idles with iac disconnected it pulls air from somewhere else.
When iac is connected it have more air than needed and this choke the engine.


'97 850 2.5 20v /fully equipped/ Motronic 4.4 / polar white wagon
'91 Citroen XM 2.0 SI /fully equipped/mandarine red metallic
History of Volvos in the family:
'71 144 S
'73 144 De Luxe
'78 244 DL
'78 244 DL
'79 244 GLE
'85 340 GLS

mescalinedreamz
Posts: 3
Joined: Wed Nov 04, 2015 8:59 am
Year and Model: 850 t5 1997
Location: Wixom, michigan
Has thanked: 0
Been thanked: 0
mescalinedreamz

Re: 850 stalls when slowing down to a light or in gear except when I disconnect the iac

Post by mescalinedreamz » Wed Nov 06, 2019 11:51 am

Vacuum guage has never changed..always showed 19 at idle. I will try to spray the engine with choke cleaner hoping for a raise in idle.



shegarty
Posts: 262
Joined: Mon Sep 12, 2011 7:38 am
Year and Model: 1998
Location: port hope
Has thanked: 7 times
Been thanked: 2 times
Canada
shegarty

Re: 850 stalls when slowing down to a light or in gear except when I disconnect the iac

Post by shegarty » Thu Nov 07, 2019 8:50 am

You'll want to check for unmetered air - so anything after the MAF. Check ALL of the intake hosing and associated clamps, you might need to smoke test the intercooler if you have a turbo setup.


current - 98 S70 T5 SE (255k km)
previous - 90 745T (400k km - sold); 94 855 T5 - (206k km - blown timing idler bearing)

User avatar
greg850r
Posts: 266
Joined: Thu May 03, 2012 5:06 pm
Year and Model: a long list
Location: Mo
Has thanked: 4 times
Been thanked: 9 times
United States of America
greg850r

Re: 850 stalls when slowing down to a light or in gear except when I disconnect the iac

Post by greg850r » Thu Nov 07, 2019 7:10 pm

Order silicone lines and replace every vacuum line you can find. If they don't solve this problem it will head off your next one.


05 Cross Country wagon
99 C70 Convertible
96 850R wagon
96 850T wagon
96 850 GLT 5spd N/A sedan
97 850R 5spd sedan
66 GTO 421SD 4spd
67 GTO 455 T400
02 Powerstroke 4x4
85 Yota 4x4
24' 454 Challenger
07 Softail Custom
02 Sportster Custom
Parts cars not included

Post Reply
  • Similar Topics
    Replies
    Views
    Last post