No acceleration Position sensor

... continuing trouble shooting of why my '89 sometimes just cuts out. Then accelerates perfectly again. I'd like to check my crankshaft position sensor as 'one' possible reason for this. Where the heck is it exactly?
Hate crawling around under the car in winter.
cheers, guenter
ps anything else I should check while I'm at it?
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...... forgot to mention 300E, sorry.
cheers

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Ah hem... you don't want to change that... You won't believe where it is located.... it is located back of the engine by the tranny with almost no space to work on it.
My friend has a 93 tha tdid the same darn thing... Drove both of us nuts...
I would start out with overload protection relay... common cause.
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Thanks Tiger. I did already. Actually I swaped it out with one in my 190E no change in the 300E and no problem with the 190E after the swap. Still going to follow your list though.
cheers, guenter
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There is one more thing I want you to check. Pull out both carpet by the driver seat. I want you to look at the big bundle of wires going to engine compartment... does it seems like been rubbing, cut, etc? I want you to find any exposed wire in engine compartment and give it a good rub to see if insulation falls off or something.
Sounds like a classic symptom of the biodegradeble wire insulation problem... but I can't recall your model year.
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    thanks, tigerm it's a '89 300E. Pulled out the carpet. finally managed to open the plastic latches on the plastic case that protects the wire bundle. they look perfect. Moved them around to see if there were rub marks.... nothing. the insulation (electrician tape... cloth type) looks as good and is as solid as the day it was put on. Next I used the propane torch on the engine compartment (carefully at first) no fireball and no difference in idle. Next I moved/lifted from car body, the wire bundle going from compyter to the infectors etc (runs along a little plastic 'tray'). No effect. tomorrow I intend to open up the distributor again and recheck points rotor etc.
....puzzling. Car runs great and am waiting for it to act up again. Idle is 'lumpy' definitely, but not horrible.
- cheers, guenter
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89 would not have the wire problem... at this point, I would suspect the distributor cap and rotor... if not also the coil.
Other thing is the OVP which I am not sure if you changed it already.
Check your charging system voltage...
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Thanks for that Tiger. Actually I did exchange the OVP with that from another car whose engine is working well (a 190E) and there is no change in either car. Haven't done the cap and rotor yet but will do asap. Meanwhile I've decided to acquire a Code reader. I assume an '89 will use OBD 1. In fact, I noticed in MBShop that the reader is quite trivial. Power from 2 pins (forget which off hand) and then read codes from either one of two pins 8 or 14. Might tell something useful. At the moment the car is running and idling perfect.... geeesh I hate that. As soon as my wife takes it somewhere with her mother I 'know' it'll stop working...
- cheers, guenter
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I thought a bad crankshaft position sensor will completely kill the engine, meaning no start at all. Also, I though this kind of 'hall' sensors (camshaft, crankshaft, ABS speed sensors, etc.) are long lasting due to the simple operation (no moving parts, simple/reliable physic). The only things that can kill them are the rust metal and cut wire. Is my understanding correct?
Guenter Scholz wrote:

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I don't know. that 'would' be a useful piece of information though. My engine does not cut out, it goes into (I don't know though) what appears to be the 'limp home mode' that I've read about but don't know anything about. In short, the engine will not rev up for a few seconds or so, and then it will motor on as if nothing had happend. Typically it 'appears' to help to take the foot of the gas and nudge it's rev's up gently.
cheers, guenter
ps I was thinking a lose connection to the crank position sensor.

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