I've been having trouble with uneven power delivery, especially at low to mid rpm. It causes jerking when crawling through parking lots and hesitation under acceleration. I believe its being caused by timing retardation by the knock sensor. This is on an '83 240 B23F with LH 2.0 (Bosch distributor, Chrysler ignition).

Checked timing - 12deg BTDC +/- 2deg or so at idle, seems pretty jumpy, but smooths out when throttle is applied.

Haynes says with key in position II/car not running, you should be able to measure 1.5V-5.0V on the knock sensor terminal. I get 0.9mV. Checking continuity on the brown wire, its good all the way to the control unit. Resistance to ground is about 47.5k ohm, so its not shorted. Next, Haynes says watch timing (with car running) and strike the manifold with a wrench - watch for the timing to get kicked down. Well, I wacked away, and got no response whatsoever.

My next diagnostic was cutting the wire near the control unit. I figured that the 1.5V to 5.0V I was supposed to be seeing was a bias voltage, and if there was some fault in the knock sensor, I should at least be able to see that voltage at the control unit with the sensor disconnected. I still got 0.9mV with key in position II. So next, I clipped the wire back together and clipped into it to watch the voltage while the car was running. I got a fluctuating value of around 44mV that dropped down into the 25mV range slowly as the car began to warm. Striking the manifold didn't seem to affect sensor output at all.

So, can any of you Bosch experts shed some light on my problem? Do I have a bad knock sensor, or is the problem in the control unit? I'm an EE, and have no qualms about opening the control unit and diving deeper if need be. Thanks...