Got a head scratcher

[Alabama]

I have a 98 ranger, auto 3.0..i have owned the truck since new, within the last year some mornings when I leave for work at 4:30 it will turn over but will not start, I can try after the sun comes up a few hours later and it will crank and run perfectly all day, same thing the next morning with same effect, I have replaced plug wires, starter, coil pack, fuel filter,..what has me baffled is it's almost like it has its own schedule..what would cause this? Any ideas.. once it cranks it's perfectly fine, I can drive it all over the place stopping and starting..until the next morning, thanks

 

[Metalcrack]

I have a 98 ranger, auto 3.0..i have owned the truck since new, within the last year some mornings when I leave for work at 4:30 it will turn over but will not start, I can try after the sun comes up a few hours later and it will crank and run perfectly all day, same thing the next morning with same effect, I have replaced plug wires, starter, coil pack, fuel filter,..what has me baffled is it's almost like it has its own schedule..what would cause this? Any ideas.. once it cranks it's perfectly fine, I can drive it all over the place stopping and starting..until the next morning, thanks

I had a similar issue a while back. Turned out the TPS was bad. It was reading as if the throttle was at 100%, causing the truck to think it's flooded/turning injectors off.

RonD posted some readings on that thread....
http://www.therangerstation.com/forums/showthread.php?t=159836

 

[RonD]

So we are assuming its a temperature related issue, not the 'time it sits between starts', right?

If it was time related, i.e. sits 5 hours and it starts, sits 8 hours and it doesn't then I would think it is losing fuel pressure.
1998 was first year Rangers were running 55psi pressure, 1997 and earlier ran 30psi.
You could try turning key on, count to 3, then turn key off, repeat 3 times and then try to start it.
This Primes the fuel system 3 times to get pressure built back up, you get about 10psi per Key On, and 20-30psi is plenty for startup, 10psi not so much

For Cold issue it could be a connection, but it would need to be a low voltage connection.
As metalcrack said the TPS could cause a no start
Crank sensor is also low voltage, and engine can't start without its 1volt AC pulse, even a little corrosion sucks down voltage
ECT sensor maybe
You are just checking connections, unplug each connection, have a look then plug it back in, this CLEANS the contacts on that connection

 

[kimcrwbr1]

Start with cleaning all the connectors under the hood with electrical cleaner and put back together with dielectric grease. Sounds like a moisture issue to me? Also sand all the grounds metal to metal you can find.