97 Explorer starting problems 4.0L

Have had problems starting occasionally. Always seems to be in the morning. It will crank for a couple of minutes without starting. Usually will start if I keep cranking. Appears like it won't start, then magically fires and runs fine. Will run fine once started.

I had problems last year and finally replaced ground cable from the battery and problem disappeared for 6 months. The cable always seemed to be corroded. It always worked fine for a couple of weeks after cleaning the post.

Now it is back. Generally seems to only be after it sits over the weekend or if it has rained in the evening. It has always started when I tried it later and Dealer can not repeat the problem by the time they get it towed in. After I get home in the evening and try to troubleshoot, it starts fine.

I had a similar problems years back on antoher car and it ended up being the Crank Position Sensor. It did not register and turn on the spark. Does this engine have the same sensor?

Any suggestions would be great.

I had the same problem with my 97, I replaced the crank position sensor, and no problems since.

If the camshaft position sensor didn't cure the problem check the crankshaft position sensor. wWhen disconnected with an ohm meter across the contacts it should go from zero to 1.