Hi everyone. Have a couple of quick questions. Can the coolant temp. sensor be replaced without taking the intake manifold off? And also just read something about the 87 year model AMM being adjustable? How do you go about doing this and what are you looking for. I guess what im saying is why does the AMM need to be adjusted, and what are you actually adjusting. Thanks a million.

BRett

Brett, the 87 uses LH2.2, so you can use an LED connected to the "CO test point" which I believe is the pink wire in the two wire plug near the driver's side strut tower. This will monitor the ECU as it switches back and forth adjusting the mixture in response to the oxygen sensor's measurements. The adjustment is physically on the AMM, but not actually part of its circuitry. If you remove the tamper cap, there's a potentiometer underneath that serves to fine-tune the match between the analog output of the AMM and the measuring input of the ECU. I think Bosch intended it to be adjusted only once, when first an AMM is paired with an ECU, but did not anticipate the degradation of the AMM as a reason to reset the adjustment.

I've done the sensor without removing the manifold by removing the AMM and its piping, disconnecting the brake booster hose, oh, and the flame trap to throttle body hose, then using a 10" extension 3/8 drive, deep 6pt 19mm socket. Surprisingly no appreciable coolant leaked, and the ECT was obviously the trouble.

Art is right, but you may not be lucky enough to be able to get a socket on the sensor. The original one fitted to mine had the external plastc bit of the sensor wider than the hexagonal section. The replacement is smaller so wioll take a socket.
Of course if the sensor faulty anyway you could just snap of the plastic to get access.

Sounds like the way they make the 700/900 gauge sensor. Not very kind if you ask me. But how did the Bosch two-pin plug fit over yours if the 19mm socket would not? Did it have some kind of extra lip at the very bottom?
--
Art Benstein near Baltimore