Volvo RWD 900 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 3/2004 900 INDEX

[<<]  [>>]


 VIEW    REPLY TO THIS MESSAGE    PRINT   SAVE 

Low idle, poor city MPG - 945T 900 1993

posted by  Brian S on  Sun Aug 7 08:32 CST 2005
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS] [RELATED]

I'm looking for help diagnosing a low idle problem with my 945T. Cold idle is a tad above 500 RPM, and warm idle is a bit below 500 RPM. The idle is smooth - just too low. Until recently, warm idle was around 600 - 650 RPM.

A related problem, I think, is really poor fuel economy in city driving - around 13 MPG. My city mileage has never been great - usually in the 16-17 MPG range, with lots of very short trips. However, highway fuel economy is excellent - just got 26 MPG on a 273-mile trip.

Today I cleaned the throttle body and IAC - no change in idle. The IAC seems to be working properly (engine died when I pinched off the hose from the IAC to the intake). Throttle position switch sounds OK. The two vac lines to the charcoal canister were in bad shape, so I replaced them - no change. Pulled a couple spark plugs, and they did not show signs of running rich.

What else should I be looking at? I know idle is set by the ECU...

Brian - '93 945T ~127k miles





THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD

New Low idle, poor city MPG - 945T [900][1993]
posted by  Brian S  on Sun Aug 7 08:32 CST 2005 >


<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.