I totally agree with the advice you've received so far. The 88 740 doesn't have a crank sensor. The 89 non-turbo and the 90 turbo started with the sensor.

If it was original, I'd tell you to go out and buy one, right now, while the car still runs.

But the failure mode is pretty similar to what happens to the distributors. The connection at the bottom of the dist (not the coil wire to the cap, but on the dist body itself) starts to fail and ground out. The plug usually gets sort of deteriorated.

I had to do one of these on my 88 a few years ago. I bought a new Bosch unit, and it never gave a hint of trouble afterward. Good used one should work too, if you can find one without damage.

Good luck with it!
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::: Rob Bareiss, New London CT ::: 92 244 ::: 90 745GL ::: 90 745T ::: 84 242DL ::: 90 745T Parts ::: Used to have : 86 244DL, 87 244DL, 91 244, 88 244GL, 88 744GLE, 82 245T, 86 244DL, 87 244DL, 88 245DL, 89 244DL!