The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

Slightly wonky idle, RPM surging during acceleration 900

posted by  MisterBLC on  Tue Jan 14 15:41 CST 2014
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Tue Aug 26 14:55 CST 2014
[RELATED]

Everyone,

I have been diagnosing an on-going issue with my wife's '94 940 Turbo. I have been slowly doing a level 0 on the car, but this issue has been persistent. The main problem is that during hard acceleration (especially when cold or under load when going up a hill for example), the RPMs will surge and you will get pulses in the acceleration of the car. You can see this on the Tach, the RPMs will surge by as much as 250 when the problem is particularly bad. Only other issue with the car is a wandering idle that stubborningly sticks around, despite cleaning of the throttle body and IAC. What has been done so far:

- Recent stage zero (~1 year ago): new plugs/wires, new dizzy cover, new timing and accessory belts, IAC and throttle body cleaned, PCV system cleaned, vaccuum lines replaced with silicone.
- New turbo (replaced due to large throttle shaft play and whining noise)
- new ignition coil
- Relatively recent (~3 years) replacement of RPM speed sensor on the back of the block

I'm some what at a loss...I am thinking of trying a new IAC to help clean up the idle, but I am not sure if this could be causing my acceleration surging. Only other idea I had was that I was getting intermittent knocking during hard acceleration and the timing was being retarded, causing the surging. Is there an easy way to see if the knock sensor is detecting knocks? Any other ideas on possible sources of the problem?

Thanks,
Brian






USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©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.