Tachometer doesn't work! :-(

[Brett Dikeman]

At 9:28 PM -0800 12/16/01, Orin Eman wrote:

>  > Similar things happen on cars with one or more damaged flywheel
>teeth.  Flywheels with a single tooth broken off seem to be
>>  remarkably common - I've seen three in about the last year.
>
>Does this set an error code?  I think it should, but I'd have to look
>at the MAC11 code to be sure.

On the 3B, yes(Bentley specifically mentions "missing teeth" as a
possible cause of a bad flywheel sensor code.)  No idea on the MCII.

Even the 3B Motronic brain gets confused...A bad wastegate frequency
valve showed up once as a "bad throttle position sensor" on my car.
Bzzzt.

And, while we're on the subject, if the check engine bulb is
installed(this is, after all, a 89+, right?), both ECUs should, when
the hall sensor goes south, pop a code and turn on the Beacon Of
Despair, yes?

I wish my light worked; ever since my ECU came back from Ned, the
check engine light has refused to go off.  I've cleared the codes,
completely reset the ECU, cleaned the ECU contacts, ground points,
and even pulled a few of the timing sensors and cleaned them up(one
had a very small amount of metal flakes.)  Cleaned all the firewall
connectors as well.  1111, bad ecu, returns within minutes of turning
the key, usually before 2 minutes.

Ned claimed "I've seen a small number of ECUs do this" and that he
can take the same chips, put them in another ECU, and they'll work
fine, and stock chips work fine in the "fussy" ecu.  He said
sometimes an ECU will work for months and then start throwing 1111.

Part of me can't help but wonder if the IA chips are socketed and
maybe there's a dirty pin somewhere, or one leg of a socket didn't
get soldered properly, etc...I'm tempted to pop that sucker open and
have a look-see, because a)the light's annoying and b)the reason I
put one in there in the first place was to see when engine faults
happen...

B
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