Motor dies suddenly, a number of times lately

[AWD Expy]

The first time was in early spring, and it restarted with no issues. A few more like that, then the past few months it won't restart until maybe 45 minutes. Other times it won't restart after I had turned the motor off for a quick errand, or visit. It always cranks over well, even sounding like it almost wants to start. It did it today after a 45 minute freeway drive. After 25 minutes, it started, but ran extremely rough during idling, so I turned it off knowing it just needed to wait. Other than that, the motor runs smooth.

3 times so far it has died on me when slowing down on freeway exit ramps. It does this about an average of once a month. I've only had this vehicle for 9 months, so I'm thinking, hoping that a new fuel filer could fix this issue. Any thoughts about this issue? Can a fuel pump be intermittent even if the connections are ok? I'll get a code read tomorrow. Thanks for any tips about this.

98 explorer xlt 4.0

 

[BrooklynBay]

Do you see a check engine light? Does the fuel pump make a sound when you try to restart?

 

[974X4BLACKSPORT]

Check your fuel pressure.

 

[donalds]

Fuel pump.
I had the exact same problems

Is my fuel pump bad 1999 ford explorer shoc 4.0. Lots of pictures on the replacement

 

[AWD Expy]

The check engine light has been on since I've had it. Code 420, 430 points towards the cats as far as that goes. Would that cause this problem on a otherwise smooth runner? No other codes.

A month ago I quickly depressed the fuel rail valve and got a good squirt, this was during one of those moments.

Usually when fuel pumps go, they are gone, and not really intermittent. But anything could be the case really.

It's almost like a cool-down period has to take place before it will restart smoothly.

The counter dude at autozone suggested a possible faulty vacuum purge valve that could cause these issues. I don't know if that is supposed to throw a code.

I figure it's due for at least a fuel filter.

 

[allmyEXes]

water in the fuel?

 

[Turdle]

Sounds like you could use a new ECT Sensor. do not confuse this with the coolant temp sender which only works the gauge.

 

[AWD Expy]

Ok. The separate sensor shows mid range on the gauge when warmed up. Tomorrow I will compare ohm readings from startup to warmup. What might be the low threshold ohm reading for a warmed up engine? If it was shorted or a way too low ohm reading, then the ecm might respond to a lean condition, causing stalling after a 70 mph, 1/2 hour ride, or after only a few minutes of being parked and shut off.

It only stalls when my foot is NOT on the accelerator.

 

[donalds]

Still say it's a week pump
Test it

 

[lobo411]

How many miles?

 

[allmyEXes]

Are you getting a P00BA code ?

 

[BrooklynBay]

Sometimes an intermittent fuel pump issue could be caused by a failing relay. The contacts wear out as they age.

 

[donalds]

Sometimes an intermittent fuel pump issue could be caused by a failing relay. The contacts wear out as they age.

So true worth switching the relay
They wear out
Even though they are self cleaning contacts
Don't last
I still say check the fuel pressure with a mechanical gauge worth it to check

 

[AWD Expy]

Back on sunday after it stalled, I was able to restart after about 30 minutes, but it idled very rough. I feel that the fuel pump is ok. For now anyway.

130k miles. No other codes were read. Today just for "fun" I changed the fuel filter. First I pulled the relay so the motor would die out. Someone had buggered up one of the line fittings at some point, making for a PITA to remove.

What should the fuel rail pressure be?

I was wondering about a ECT...would it/should it, throw a code if it is seeing out of range data? But after some cool down, would that code auto-clear?

 

[donalds]

I posted a link above I had the same problems
Lots of info how to test the pump and all and the fuel pump fix
I let this overheating pump bug me for like two years

It will do it on hot days worse
Give it like 20 minutes to cool off or pump some fresh gas to cool it off then you can drive away