97 ZJ Cranks, won't start

97 ZJ 5.2 Limited.
Was fine yesterday, this morning got in to go to work and it cranked like c razy but wouldn't start. Checked codes, showing 12, 21, 55. Checked all u
nderhood fuses, all good. Swapped relays around, no joy. Standing behind it I can smell gas after cranking it for a while. No obvious drips underne ath. Any thoughts?
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On 5/27/2014 12:18 PM, J. Clarke wrote:

Gotta have fire, fuel, air and turbulence. Sounds like the spark is missing.
Lynn
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J. Clarke wrote:

12 = battery disconnected within 25 start/stops 21 = O2 sensor 55 = end of codes
None of those are critical or would prevent starting.
First check that your battery connections are nice and clean. Then crawl under and check for a burned wire to the O2 sensor(s).
I suspect that isn't your problem though. Likely the one thing that isn't checked which is lack of spark. (i.e. dead coil)
You can test it with one of these. http://www.harborfreight.com/inline-ignition-spark-checker-69014.html
The other code that didn't throw could be the dreaded CPS (Crankshaft Position Sensor) fault. That will get you, but usually only happens when hot.
First check spark.
--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
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On Tuesday, May 27, 2014 6:00:24 PM UTC-4, DougW wrote:

Had Geico to it to the mechanic and let him deal with it. Just as glad I did--turned out to be the fuel pump--another big repair to fix a small part.
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