2003 Ford Explorer Cranks But No Start

[Andy1416]

Hello All:

My Aunt's 2003 Ford Explorer Cranks But Wont Start and these are the tests my Uncle performed:

He texted for spark and there is spark, he tested the fuel injectors with the noid light and it lights up. He tested the voltage in the supply circuit for the electronic sensors and he got a steady 5 volts. He tested the fuel pressure rail for pressure and there was zero pressure, he tried thumping on the tank, and it didn't start the pump, the pump is brand new and only ran for a day and a half. The mechanic told my Uncle the fuel filter was dirty and my Uncle will update me tomorrow if the mechanic changed the filter or not.

Any help from you guys would be greatly appreciated, thank you very much for your time.

 

[donalds]

Sounds like a bad fuel pump
Reading your other post makes me think pats

My next step
Jumper the fuel pump relay see if the pump is actually working

 

[Stynx]

Stuff like fuel pumps usually don't die if they are working out of the box but stranger things have happened. Test it first then work your way down the line. If the fuel filter has never been changed it's WAY overdue. When I did mine, thick black gunk was running out.

 

[Andy1416]

Sounds like a bad fuel pump
Reading your other post makes me think pats

My next step
Jumper the fuel pump relay see if the pump is actually working

What's Pats and what's it got to do with this?

 

[donalds]

Passive Anti-Theft System (PATS)​

PATS Will keep your truck from starting
By disabling stuff like fuel injection and or fuel pump

 

[Andy1416]

Passive Anti-Theft System (PATS)​

PATS Will keep your truck from starting
By disabling stuff like fuel injection and or fuel pump

What usually screws up on the pats system? Is there a sign or something showing that pats has been activated or something?

 

[donalds]

rapid Flashing red light on the dash

Most likely a key chip try a different key

 

[imp]

What usually screws up on the pats system? Is there a sign or something showing that pats has been activated or something?

With key off, red indicator on dashboard blinks on, then off, every 3-4 seconds. Turning key to ON will cause the red light to illuminate solid ON for 10 seconds, if no further key movement occurs, then off, if key is turned to START, red light goes off, engine cranks normally.

If PATS detects wrong key, red light flashes rapidly on and off when turned to START, no engine crank will occur, starting is disabled.

 

[Andy1416]

Thanks for everyone's help, my Uncle did more digging on her truck and turns out her fuel inertia switch was melted. He replaced it with a better one and it runs and everything.

 

[DaaQ]

Thanks for everyone's help, my Uncle did more digging on her truck and turns out her fuel inertia switch was melted. He replaced it with a better one and it runs and everything.

Could you elaborate a little more on this because I have same issue, crank no start, and parts dealer said the inertia switch almost never goes bad.

I've yet to check rail pressure, and change fuel filter. (My highest suspect atm)

 

[Stynx]

Could you elaborate a little more on this because I have same issue, crank no start, and parts dealer said the inertia switch almost never goes bad.

I've yet to check rail pressure, and change fuel filter. (My highest suspect atm)

Start with the filter. It's the cheapest, easiest thing to replace and probably is overdue anyway. Any codes?

 

[J_C]

Is the inertia switch still inside the passenger footwell trim panel (right side) on a 3rd gen? Either way, can check inertia switch for 12V getting to it (when pump should be running, only a moment at key to run position) and 12V getting out, or check for very low resistance at any time between input and output contact, as it's always closed circuit until tripped from an impact.

Otherwise if there's a a valve to check pressure on the fuel rail, easier to do that before swapping the fuel filter out. Autozone among others has a free (with deposit) loaner gauge to do it. Also easier to spray some starter fluid in the intake to see if you get any cylinders firing while cranking.

However crank no start can have many causes, just because someone else had problem X, doesn't mean you don't have problem Y or Z instead. Fuel, spark, air ratio, timing.