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!

Hunting idle at cold start

Help, Advice, Owners' Discussion and DIY Tutorials on all Volvo's "mid era" rear wheel drive Volvos.

1975 - 1993 240
1983 - 1992 740
1982 - 1991 760
1986 - 1991 780
1990 - 1998 940
1990 - 1998 960
1997 - 1998 V90/S90

Smar1991
Posts: 6
Joined: Mon Dec 03, 2018 5:02 pm
Year and Model: 1993 940
Location: VA
Has thanked: 1 time
Been thanked: 0
United States of America
Smar1991

Hunting idle at cold start

Post by Smar1991 » Tue Dec 04, 2018 4:54 pm

My 93 940 nonturbo has a hunting idle at a cold start. If I let it run for about 10 min it settles down, but initially it revs constantly from .5-1 rpm. Additionally, I've noticed that I have a pretty sluggish acceleration (more than the normal sluggishness of these nonturbos). I put in new plugs, wires, vacuum lines, and distributor cap and nothing's changed. I know the b230 isn't known for having the smoothest idle, but I'm worried the ecu might be going bad since it has 242,0000 miles on it. Any ideas?

User avatar
RickHaleParker
Posts: 3439
Joined: Mon May 25, 2015 2:30 pm
Year and Model: See Signature below.
Location: Kansas
Has thanked: 3 times
Been thanked: 412 times
United States of America
RickHaleParker

Re: Hunting idle at cold start

Post by RickHaleParker » Wed Dec 05, 2018 4:06 pm

Idle air control valve (IAC). You might try cleaning out the IAC with MAF sensor cleaner or Carb cleaner.

It could also be leaks in the intake manifold gasket that seals up when the engine warms up. You can locate intake manifold leaks with starting fluid. Spray the starting fluid around the intake manifold gasket when the engine is idle hunting. A leak will suck in the starting fluid and you will hear the engine surge.


Idle air control valve (IAC).
IAC.gif
You do not have the required permissions to view the files attached to this post.
These users thanked the author RickHaleParker for the post:
Smar1991
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

Post Reply
  • Similar Topics
    Replies
    Views
    Last post