OK here is a very basic layout of how the relays work to power the computer.
There is a large fuel pump relay under the dash. This is located under the
drivers dash between the steering column and the left side of the car. It's usually a large green relay with six terminals. This relay feeds power to the
lambda relay. The lambda relay is located on the relay bar in the left inner
fender. It's the small dark gray or silver relay toward the strut tower. This
relay gets turned on by the fuel pump relay. Once this relay turns on it turns
on the fuel injection components on the engine and turns on the computer. So,
if this relay is bad or the fuel pump relay feed to this is bad then you don't have a buzzing frequency valve. I've also had the terminal in the computer
connector for power from the lambda relay push out of the connector. If the computer doesn't get power the frequency valve won't be buzzing. Hope this helps you.

Dave 82 242ti 282k mi.

Hello,

In my Haynes (green one), there is a whole section (well used) on the B21FT. I would have commited suicide if I didn't have that book when I had an '83 244T. The Jetronic computer is found behind the passenger kick panel. Clean the connector there and see what happens. Ultimately I replaced the ECU with a good used unit when mine was running rough for no reason. The black smoke could be caused by a grossly over rich mixture or bad gas. Unload a can of carb cleaner while revving the engine to clean things out and get an allen wrench that fits the mixture adjuster. Half turns at a time with a sensitive voltmeter connected to the live output of the O2 sensor, tune to approx .8 volts at idle. Please bricksters if I am wrong with that figure correct me - it's been 4 years since I have had to tune one of those pesky 240 Turbo's. Right for rich, left for lean.

Happy Bricking!!!

Richard

87 245 DL 350,000 km
82 242 GLT 121,000 km

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