Ckp gone wild. No.start no spark.

[Little_hoopday_that_could]

Ok the little hoooday is the sport but this is a ride I just picked up for the family. First it's the crap 4.0.sohc motor. When purchased had a bad antifreeze leak that required changing out the thermostat housing and two sensors. First run down the road in five minutes died at idle. No start. I had same problem with sport. Had my son crank the ignition while I jiggled the wiring to ckp and it fired up and died. Crap all over it from the antifreeze leak. Thoroughly cleaned the area and fired up and no problems for 500 miles of driving. This morning no start. Checked fuel pump and it kicks on. Checked coil and power in but no pulses out on the three negative terminals. Changed ckp. Saw that some idiot previous must have thought the top bolt of ckp was a water pump bolt and took it halfway out and never retightened. So egged.out partially stripped top bolt but when done exactly right still tightens down properly. Changed ckp and still no start and still no pulses at 3 negative terminals at coil. Wiring issue to ckp terminal or bad coil or what are the chances of getting a brand new ckp that's bad? Ghost in the machine and need my hoopday rolling!! Help me oh explorer gurus your my only hope.and yeah the other Explorer sport we got is the fastest hunk of junk in the Galaxy! But thats the 4.0 ohv bullet proof masterpiece. And that never no starts on me. Shake rattle and roll all day and all night and smoke damn near anything off the line with the front shaft pulled haha.

 

[Jon94]

If you hook up a multimeter to the two terminals on the crank sensor, you should get 5V AC while cranking the engine. If you get 5V, the sensor is good. Search around online and try to find a pinout of the ECM for your Explorer. Find which two wires go to the crank sensor. Back-probe the wires and see if you're still getting 5V AC while cranking. If you get 5V at the ECM, the wiring is good and the signal is reaching the ECM.

I had a problem with my Explorer - the ECM was acting like it wasn't getting a signal from the crank sensor, and I confirmed the sensor and wiring were good and the signal was reaching the ECM. It was a bad ECM. Replaced ECM, had a dealer re-program the PATS, and it was fixed.

 

[Little_hoopday_that_could]

If you hook up a multimeter to the two terminals on the crank sensor, you should get 5V AC while cranking the engine. If you get 5V, the sensor is good. Search around online and try to find a pinout of the ECM for your Explorer. Find which two wires go to the crank sensor. Back-probe the wires and see if you're still getting 5V AC while cranking. If you get 5V at the ECM, the wiring is good and the signal is reaching the ECM.

I had a problem with my Explorer - the ECM was acting like it wasn't getting a signal from the crank sensor, and I confirmed the sensor and wiring were good and the signal was reaching the ECM. It was a bad ECM. Replaced ECM, had a dealer re-program the PATS, and it was fixed.

 

[Little_hoopday_that_could]

Thanks alot for that. The ecm I was thinking tracing the wires to already and had just looked it up. Btw in case u ever need this information it's pin 21/22 for the two wires from the ckp sensor. But did not know about how to test the voltage to double check the sensor. Thanks and will update once done or found out that it's not those and still an issue. This one definately has me doing some thinking. Not one of my biggest strengths but I'll try to manage. Off to go fry some wiring. Thanks again.

 

[TexasBlonde]

We are chasing a similar electric charge drain on our 1997 5.0 v-8 explorer. We have replaced the starter about a year ago, has a brand new battery and new alternator. No lights or doors were left ajar to drain the battery. The battery was DOA and Explorer would not start. *sigh*

 

[Little_hoopday_that_could]

We are chasing a similar electric charge drain on our 1997 5.0 v-8 explorer. We have replaced the starter about a year ago, has a brand new battery and new alternator. No lights or doors were left ajar to drain the battery. The battery was DOA and Explorer would not start. *sigh*

 

[Little_hoopday_that_could]

Check the ground coming off the battery itself and any rot to the wiring along the front driver's side frame rails where the wiring goes down to the starter. I actually had a similar problem with a family members Lincoln continental. There was exposed positive and ground wires that came in contact with the frame rails occasionally and would arc and short out. On that one and how wierd is this, the actual from frame section became completely positive and would light up a test light when I finally found the problem..it's time consuming but that's what it is and would bet money on it. They don't always short out and may only happen on occasion in perfect condition like rain or snow that would amplify any lack of ground issue. Hope this helps or atleast gives you a new direction to look.

 

[Little_hoopday_that_could]

Oh and sorry I didn't get chance to post myown reply yet because this helps has decided to come back out of the grave kicking and screaming and has some bugs to work out. But the problem was the actual wiring and pigtail connector. It was worn out and testing the voltage proved that it was I ly intermittent getting steady voltage and depending on what horrible Jersey road I was in being bounced around on would cause it to lose a good connection and do a no start the next time I tried to fire it up. Live and learn and change the pigtail when I changed a sensor..silly me!