Original problem was what I guess they call that "3-4 flare". While accelerating normal, the transmission will practically skip 3rd gear and go to fourth. Read in several places that maybe the modulator valve is going bad.
Replaced modulator valve,(new one looked kind of different - old one had this rod with a spring around it sticking out the end that goes into the transmission, new one didn't have this at all; made sure it was correct part, mb said it was, but couldn't or wouldn't explain why there was a difference) Now I'll try and accelerate normal, and before I even reach about 20 mph, I'm already in fourth gear.
Checked vacuum, 20Hg, good from what I hear. Checked the three way valve on top of the valve cover, good. Checked the vacuum valve on the ignition pump, and it's good. Made sure vacuum was getting down there to the valve, and it is. I know there's an adjustment on the modulator valve, but how to set it? I tried several positions on it and test drove each time, but with no avail. Noticed from Haynes manual that I didn't have a "throttle linkage control pressure rod". Could this have anything to do with this? And nothing is hooked up to that 'bell' on top of the injection pump. Never was able to downshift from flooring the accelerator, even after intentionally hitting that switch behind the pedal. I'm pretty sure the tranny oil is at correct level.
Can anyone help? 123k miles on car. Have this nasty feeling tranny is going to have to be replaced.
'80 240D (sold) wish I didn't.
'85 300D (240K miles)