OK - For the last 10 years the Ranger has started perfectly every time. Last week, for the first time, I turn the engine over and it would not run. It sounded like none of the cylinders were firing so I pulled a spark plug, grounded it and turned the engine over, no spark. After half an hour of fiddling with connectors and swearing under my breath the engine started and ran like it was new. This all happened (BTW) when I was 40 miles from home so after the engine started I drove it home without any trouble. The next morning, same thing, the engine would turn over but not run. No spark. Between then and now, I've checked the coil pack by ohming out between the Batt+ terminal and each of the three coil primaries (same connector) and I get 2.5 to 3 ohms. No opens or dead shorts. Next, I checked the crankshaft sensor for output by looking at the two terminals with an o-scope. While cranking the engine over I'll see a steady sine wave output - proportional to the crankshaft RPM. Outputs everytime so I rule that one out. BTW, when the engine is in this failure mode the PCM does not generate any error codes or check engine light - nothing.... So I'm thinging that may it's a wiring harness connector problem or perhaps a flaky ground connection. Any suggestions as to the root of this intermittent problem would be greatly appreciated. Thanks. Chris. My 99 Ford Ranger has had problems w the coil pack/spark plugs on and off for the past two years. I have brought it to Ford and replaced the coil pack/ sparkplugs numerous times. It there anyway to fix this problem for good?
What is the engine size? Have you checked the ignition module? Check the output of the crank sensor at the ignition module to verify wiring integrity. The signal is shielded so insure there is no break in the insulation.
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