so I find out one of my neighbors has a beautiful 1982 240D, only 150,000 miles. It's a grey market car he bought from the original owners who imported it. He says a few thousand miles ago the crankshaft failed, so his dad did an engine swap with a 1984 California 300D. He said it had shifting problems, so I said to bring it on over. Holy cow! There were vacuum lines going everywhere, nowhere, and who knows where... (obviously none getting to the transmission modulator), an electric fan that runs all the time, and two temperature probes disconnected, though he says it still runs hot..lol. After spending a while scratching my head, I just re-plumbed the thing in the most correct manner possible. Instantly he had the smoothest shifting 300 I'd ever been in. The most unusual thing I saw, and what I have a question about was a line going from the ALDA to the main vacuum supply. I'm talking about a barb fitting on top of the banjo bolt for the line that runs from the intake manifold to the ALDA. Is this just someone's way of fooling the ALDA into thinking there's no boost? Obviously this was robbing most of the vacuum from the system, and he said there was a slight reduction in power after I terminated it, (small price). Anyone else seen this?

Forgot to mention, he was so happy with the results of the transmission, that he gave me the cruise control actuator from the car. I was teaching him what all the parts were under the hood, and when I came to the actuator I mentioned that I was in the market for one of those. When we got done he says "just take this one", I tried to talk him into keeping it, but he said he doesn't like cruise control, and this one was abviously not connected to anything (it wasn't). So now I have cruise

I believe that there is some confusion on the terms. The banjo bolt takes manifold pressure and sends it to the overboost protection valve. From there it goes to the ALDA. There is no connection to the main vacuum supply AFAIK. The manifold pressure serves to signal the ALDA to provide additional fuel.

Can ya scarf the amplifier for me?

He won't need that now that the actuator is gone

Thanks...

Cheers,

Bill

Hey, I'll ask about the amplifier. Yeah, there is supposed to be a switch in line between the intake manifold, and the ALDA, and there isn't, and I cannot understand why the banjo bolt on the ALDA was connected to vacuum. I'm going to try to help him get this thing straghtened out.

Yep, you've got a right mess on your hands.

The reason that the banjo bolt is not connected through the overboost protection valve is probably because the valve got clogged so they bypassed it. Why anyone would connect the vacuum system to manifold pressure is a mystery.

The vehicle should be quite slow because it has no fuel enrichment.

The reason that the overboost protection valve on the firewall wasn't connected is that there is NONE on a 240D! No turbo.You need to get it from the donor car. You'll need to cobble an electrical source; the sensor should still be on the "new" engine (intake manifold, rearward of air cleaner). I recommend doing it right, although some just bypass it and hope that the wastegate doesn't stick closed.

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Never fix the car until the title is transferred.

Ken300D

__________________
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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

I knew I should have offered to buy the car before fixing it!
His aux fan is permanently on, the EGR is there, but none of the vacuum lines, half the electrical connectors don't match up or go anywhere and the list goes on and on. Despite all this it drives quite nicely and looks gorgeous.

%$#&**$# Smack me in the head.

Of course the 240 had no turbo and therefore had no overboost protection valve. jbaj007 is right on the money.