my 02 Ford Ranger Edge 3.0 will once in a great while turn off. Once when I was idling through a parking lot (did not restart for an entire day without doing anything) and once when I let it idle for 10 minutes (restarted on the 2nd try). Happen a few other times but I have tried to replicate situations and could not repeat it. I had it idle by itself for an hour and it was fine. I have put 100's of miles in between these circumstances. I kinda been chasing this, along with other problems)
I have a new fuel filter, fuel pump assy., two new heads, new cam sychro, plugs, wires, crank sensor, and coil. I've replaced the fuel pump relay with a Ford OEM, I also have installed my own external Fuel pump relay (bypassing the stock one) to address this issue ( Fuse box was damage in that section, replaced the fuse box also)

So my question, I believe its the Fuel pump losing power, but at all these times, I could not verify that. Is there something in the engine code that will tell the fuel pump to shut off like a oil pressure sensor, coolant sensor, knock sensor, etc etc. I have went to every connection and refitted it, and wiggled.

Thank you for your time

 

Yes, there are codes if fuel pump loses power when it should have power
P0230 Fuel Pump Primary Circuit Malfunction
P0231 Fuel Pump Secondary Circuit Low
P0232 Fuel Pump Secondary Circuit High
P0233 Fuel Pump Secondary Circuit Intermittent

"Primary" is the fuel pump RELAY, the part the computer controls
"Secondary" is the 12volts to the fuel pump

Manual or automatic?
Do you have a Tachometer on the cluster?

When the engine stalled did the CEL(check engine light) and the Battery light both come on?
CEL should come on at 0RPMs if Computer is still powered up, no CEL when engine stalls means computer was powered off, which is why engine stalled
Battery light and CEL both not coming on means power was cut to engine systems, possible ignition switch issue(under steering column)

After the stall and no restart look at the CEL
CEL should come on with key on every time, that means computer has powered up
CEL should go OFF as soon as you activate starter motor and engine is spinning, that means computer is getting a timing signal from crank sensor, no timing = no start

When you say "no restart" does that mean starter motor works but engine won't start?
OR that the starter motor doesn't work?


Computers fuel pump control is fairly simple
Key on and power up(CEL on) of the computer will activate the fuel pump relay for 2 seconds, and only 2 seconds, it will do this each time key is turned from off to on, 2 seconds each time, you should be able to HEAR the fuel pump run for those 2 seconds, its not quiet
So while its working cycle key off and on as much as you need to so you KNOW what it sounds like, in case there is another stall

Computer will turn on fuel pump relay full time when RPMs are above 400, cranking speed is 200RPMs, so fuel pump does run until engine starts, so above 400RPMs
Then fuel pump stays on until key off or if RPMs drop below 400, crank sensor is RPM sensor
Temp overheating wouldn't cause computer to stall the engine
There is no oil pressure shut off either

PATS(passive anti-theft system) does control fuel system, in 2002 PATS is in the Computer
PATS is only active when Computer is first booted up, key on
There is a THEFT light on the dash, with key on it should come on and then go off if the key in the ignition passed the PATS test
If the THEFT light starts to flash rapidly then the Key did NOT pass the test and no start
But once the key passes the test PATS is off line, no more tests until key is shut off and then turned on again


3.0l Cam sensor/synchro is also the Oil Pump drive, so on some years failed cam sensor can cause engine stall, but never seen that myself just read about it so not even sure that exists

 

Thank you Ron, You been helpful to me before. I don't have complete answers to your questions but I know where I can procced. Unfortunately, everytime this has happen, I am not able to diag or make note of the CEL light. I will put a scan tool on it tonight.

Thank you very much