| [GMCnet] Shifting and Vac Modulator [message #99010] |
Wed, 08 September 2010 14:46  |
Ray Erspamer
Messages: 1707
Registered: May 2007
Location: Milwaukee Wisconsin
Karma:
|
Senior Member |
|
|
Good Afternoon Guys
Okay, I'm not sure I have this all 100% right, but I'm trying to figure out
what's going on.
As I understand the way the vacuum modulator works, it monitors engine vacuum.
Engine vacuum reacts very accurately to engine load with high vacuum produced
when the engine is under light load and diminishing down to zero vacuum when
the engine is under a heavy load. When an engine is under a light load or no
load, high vacuum acts on the modulator which moves the throttle valve in one
direction to allow the transmission to shift early and soft. As the engine
load increases, vacuum is diminished which moves the valve in the other
direction causing the transmission to shift later and more firmly.
My Problem
My transmission shifts extremely early, to the point that if I take off from a
stop sign, before I get through the intersection I'm already in 2nd gear, if I
cross the intersection and head up a hill, I have to manually downshift to get
up the hill at a decent pace.
In analyzing the situation, could my problem be that my auxillary brake booster
vac pump is not connected right and is not segregated from the vacuum being used
on the vacuum modulator??
I started investigating things thinking I could have a bad vacuum modulator,
then this came to mind.
Thoughts?? Thanks for the help.
Ray
Ray & Lisa Erspamer
78 Royale Center Kitchen
TZE368V101144
Wauwatosa, Wisconsin 53226
Email: 78GMC-Royale@att.net
414-745-3188
Web Site: http://ray-lisa.page.tl/
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Ray Erspamer
78 GMC Royale Center Kitchen
403, 3.70 Final Drive
Holley Sniper Quadrajet EFI System,
Holley Hyperspark Ignition System
414-484-9431
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
