ALDAs are meant to be removed and discarded if they start causing issues. Don't repair them, chuck it and don't replace it. Leave it off. They're a driver convenience "anti smoke" device, a nanny thing, that when if you press too hard on the pedal, you don't blow black. It's all great in theory, but when there's any ALDA issues (seals, etc) the problem shows up as loss of power. Remove the ALDA goodbye issues. When it's off, if you press too hard on the pedal you blow black. So learn how to drive by not over fueling.. get to know what the car is capable of and don't think pushing more fuel will help. When you see black pouring out the back end, that's just unburned fuel - pure wasted money.

The shut-off valve is a thing that can mysteriously rob power, if it's semi-depressed. Next time you're suffering from power loss pop the hood and note the position of the lever. Manually pull the "throttle" cable to rev the engine see if the lever bobs around. Check vacuum on the shut off circuit.

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Cheers!
Scott McPhee

1987 300D