So I have an 03 5.4. I was driving home and all of a sudden my truck starts dying. I'll press the gas and it would go then stop and it finally died so i pulled off to the side of the road. I tried to start it again and it turns over but wont start. I did have a code before hand for about a month but never had a problem. Code is P0125. "Closed Loop Fuel Control Insufficient Coolant temp"
Other info, Have a half tank of gas, replaced starter not too long ago and also replaced fuel pump about a month ago
thanks guys

 

My first suspicion is that the fuel pump stopped, either by becoming inoperable itself or because it lost power. It could lose power because of a loose / bad wiring connection or because the system shut it off. You can spray some starting fluid into the throttle body to see if it will start & run briefly, then you'll know it died because the fuel shut off.

Most likely, I figure the fuel pump failed. But you want to check for the "silly stuff" like a loose wiring connection first, or you'll buy a new pump and it won't work either.

 

Will it start after totally cooling off, cold ?

 

I'll try tomorrow morning and see

 

Other than that, the PO125 is most likley due to being low on coolant. That's the common culprit. Could be the sensor which would be the CHT sensor.

I agree with TW98-V6-42 post above. Plan on checking the pump and relay if it doesn't start or even if it does. It's how these pumps go out, they start with freezing up, then die completely.

Yea, even though it's a new pump, go through the procedure. It's not often you get a bad pump this new, but definitely possible. Check it out and as said all connections to it.

Tell us what you find.

 

Won't start cold, tried starting fluid that didn't work. And everything else looks fine. Would a fuel filter cause this?

 

It could. It's definitely not getting fuel.

 

If it didn't start after you sprayed starting fluid into the throttle body, that says to me that you have a problem other than fuel delivery. You put a super-easily ignitable "fuel" into the engine and it didn't ignite. Sounds like your spark plugs aren't sparking. I guess the ignition system can have a sudden complete failure of some component, but often these type failures are due to the engine control electronics (the computer & it's associated sensors).

EDIT: I should have also said that something "silly" like a bad ground or wiring connection is a common culprit with sudden, complete ignition system inoperability.

 

Yea starting fluid doesn't work with these trucks if it's not getting fuel. I'm not totally sure why that is.

 

Interesting... good to know.