I have a starting issue with our older Explorer.
Vehicle:
1998 4.0 SOHC
Owned for 6+ years, no major issues to date.
225K miles, well maintained.
Problem:
Vehicle will start fine on first start of day, or any other time after being parked for enough time to cool off like it is in the AM. Example, drove for about an hour and stopped for a hamburger. In restaurant for about 15-20 minutes go outside to vehicle, no start. let sit for about another 20 or so minutes and starts fine. Runs good, NO code given, ever. Has happened multiple times. Fuel is present in fuel rail as I poked Schrader valve in fuel rail and gas is present and with very good pressure. My guess seeing NO check engine light ever is something ECM or ignition coil related?
Haven't tried to troubleshoot yet, holiday, work blah, blah.
Any initial ideas of a common problem concerning no start with warm engine?
Thank you in advance.

 

"No start" means what?? Does it crank normally, but fail to start? Or does it refuse to crank until things are cooled down?


If the former, think about an intermittent electrical problem, heat related. If the latter, consider possibly a heat-related problem in the starter itself. Just a few thoughts. impish

 

Yes, no start means cranks fine, no run.

 

Initial thought is fuel pump. But until you measure fuel pressure (with a gauge) and check for spark, that's just a guess. If no spark, then I'd suspect Crankshaft Position (CKP) sensor.

-Rod

 

Will try the CPS and I'm thinking the starter solenoid might be suspect. Vehicle has had battery cable problems, since fixed with new parts. Wouldn't intermittent fuel pump issue kick out code? I also have a fuel filter from a while back that needs to be put in, too many vehicles to maintain.

 

If you are ordering/requesting from a parts store, be sure to emphasize "Crankshaft" position sensor. The acronyms CPS and CMP sensor are often used for the Camshaft position sensor. The cam sensor can cause misfires and idle issues but would not be a typical cause for a no start condition.

Also, I hope you plan to measure the fuel pressure, not just go off of the "enough pressure to spray" method.

-Rod