On May 12, 11:29=A0pm, jonb55...@[EMAIL PROTECTED]
wrote:
> Hi Group,
>
> The other day my car would not start. =A0The battery is fully charged
> and the starter cranks well. =A0My friend and I did some preliminary
> diagnosis with which we discovered:
>
> 1. There is 12V at the ignition coil (both wires to ground).
> 2. The resistance/impedance numbers of the coil are within spec.
> 3. There is no water in the coil, we displaced it with lubricant and
> the protective boot looked ok anyway.
> 4. We hooked up a 2 different spark plugs to the output wire of the
> coil (the wire that goes from the coil to the cap) and then grounded
> it and turned the key into the ON position (but not the start
> position) and did not get any spark.
> 5. There is fuel in the rail.
>
> My question is, if there is 12V at the ignition coil, and the
> resistance numbers are ok, could it still be a bad coil, or does this
> point to something else like a bad DME/ECU, a bad DME Relay, a bad
> crank position sensor or speed sensor?
>
> I've read in other posts that when these sensors go bad, there is no
> spark... but did the authors of these posts mean to write that when
> these sensors go bad, there will NOT be 12V at the coil? =A0Please
> help. =A0Thanks.
Could be any of these, but I would try the DME relay first, this is
the classic failure of these vehicles. I had a similar failure on my
'88 and it ended up being a combination of bad coil and poor solder
joints in the DME (likely caused by the bad coil overheating the coil
driver) but if you are confident in your diagnosis of the coil as
being good try the DME relay. You can bypass it tem****arily, look for
a procedure on Clark's Garage.
nate
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