I recently purchased an 85 300sd. The problem i have is it will not shift into second untill itreaches 4300rpm's. same thing with 3rd and drive. I looked at the vacuum diagrams which are posted and am pretty sure everything is in the right place.

i am not getting any vacuum out of the amplifier on the hose that goes to the transmission. I checked the hoses and connectors and they are good.

The other line going out of the top of the amplifier goes to a T. one side goes around the front of the engine and other goes toward the windshield and is blule and white. it hoods into a 4 way connector that hooks into a nipple on the white platic part of the main line at the firewall. I hooked my vacuum pump up to this line and it will not hold vacuum, being that it is also hooked to the vacuum amplifier how is the amplifier able to hold vacuume when this piece is directly connected to it.

should this white and blue line hold vacuum?

I also unhooked the line going to the modulator and it made no difference in the shifting. I unhooked the cable on top of the engine and it made no difference in the shifting. I also unhooked the kickdown switch, still no difference.

any advice will be greatly apprecieated.