I took the advice from somebody on this forum and just did away with the black box on the valve cover. I just bypassed it by plugging together the lines that went there and came back to the same place.

Now I have absolutely no power.

Trans shifts early and I never get up to speed.

Everything was fine until I did the vacuum line switcheroo.

I was under the impression that I could reduce my risk and simplify things if I did this but so far that has not been the case.

Should I just hook it back up?

__________________
1993 W124 300D
-297K on the clock as I type this.

Oh yeah, this is on the '81 300D.

__________________
1993 W124 300D
-297K on the clock as I type this.

Check your bowden cable, you might have knocked it loose.

__________________
1985 CA 300D Turbo , 213K mi

you shouldnt have hooked the lines together. romove lines from the rubber t's above inj pump going to switch. plug rubber t with a golf t.

What about the lines that come back from the switch?

__________________
1993 W124 300D
-297K on the clock as I type this.

Follow rick's advise, just plug everything off, not together. I used a new three way connector in place of the four way, and just a piece of hose where the three way used to be. These near the firewall. I have the same set up on both of my cars, an '81 may be different. The vac lines are independent of the Bowden cable.

__________________
83 SD

84 CD

My 81 had NO bowden cable. The black box controlled 2 things. EGR vacuum signal depending on throttle angle and metered vacuum to the transmission. So, by removing all of this, you now have no adjustable vacuum to the vacuum modulator, so it shifts too early. On my 81 I simply disconnected the source hose from the black box to the EGR temp sender on the thermostat housing. I left everything else intact. The bypassing of the black box only works on auto trans' with a bowden cable.

__________________
81 300CD (sold) 1972 280 SEL 4.5 (sold) 1966 250 S 4 spd (sold) 1974 450 SL (sold) 86 BMW 325ES (sold), 1973 280C (sold) 1988 300 SE.