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 

Green/black check valve on ignition vac. line - orientation question 200 1983

posted by  gt6 on  Sun Mar 23 08:27 CST 2003
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Wed Jul 17 19:44 CST 2013
[RELATED]

I've been playing with my ignition timing lately, trying to see how far I can advance it with 94 octane, and I noticed that the green/black check valve was oriented with the green side facing the ignition computer. I seem to remember that it should face the other way. I ran it that way, and ended up with some seriously hot oil and elevated coolant temps! So I broke out the timing light.

With all vacuum to the computer disconnected, I ran the engine up and down - timing seemed to change based solely on RPM, maxxing-out around 30* advance. I connected the valve with the green side facing away, and now the advance climbed rapidly off the timing scale, maxxing somewhere around 50*. Running the valve in the original orientation (green towards computer), the behavior seemed to mirror the no-vac connected case, maxxing out around 30* advance.

Can anyone out there confirm the OEM-spec orientation of this valve? And what exactly does this valve do? It seems to allow airflow in one direction, and not the other, but I don't see how this would really be desireable in this case. Is there a reason why I wouldn't want a direct vac. line from the computer to the manifold? And what should the max ignition advance be at higher RPM? I confess, I'm somewhat ignorant about ignition timing curves...
--
Speed Racer, '83 240 R, '74 164 E, '93 940 OL1 (Manchester, CT)






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.