View Single Post
Old 08-01-2015, 02:59 PM
Zacharias's Avatar
Zacharias Zacharias is offline
Not so amused
Join Date: Apr 2010
Location: West Quebec
Posts: 4,025
Originally Posted by mrbison View Post
Really? When you press the accelerator, the linkage moves the arm in the same way - why would it be different? On a gas engine the vacuum would be close to zero at full throttle so the VCV should mimic the same kind of situation. Anyway, I'll do a test drive and see what the car is shifting at. Could be the linkage arm needs adjusting. Anyone know if the VC is supposed to be at 0 when the car shifts?
The entire purpose of the VCV is to bleed off vacuum, so as to have the vacuum at 0 at the point when the car should shift. That is why it is there. If it is out of adjustment you will never get the transmission to shift as it should.

What you wrote suggested you had the car running, stationary, when you tested the VCV. If so, whatever movement you made of the linkage was nothing like driving conditions. An unloaded engine sitting still with the car in P or N would severely over-rev if you moved the linkage as far as it would go under driving conditions.

2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22
Reply With Quote