2006 Ford Explorer Starts with starting fluid and runs fine won't start on it's own cold

[tech7000]

I have replaced the Throttle Body, fuel rail sensor, fuel pump regulator, MAF sensor, fuel filter, fuel pump relay in the fuse box, and the air filter. The engine cranks but will not start cold unless I use starting fluid. Once it starts it runs great, smooth, lots of power and no issues and I can drive for hours. When I stop for 15 - 20 minutes it will still start good - however when it cools down it fails to start again unless I use starting fluid., Acceleration is excellent and no hesitation or loss of power. Is there something else that can cause this issue ? Could the coolant temperature sensor or crank shaft position sensor cause this ? Any help would be greatly appreciated.

 

[Fix4Dirt]

can you get fuel pressure at the rail?

 

[94Eddie]

I had a similar problem. The engine would flood many times when trying to cold start it. When it was warm it started and ran fine. I checked fuel pressure, changed the fuel filter etc. and nothing worked. Then I decided to change the spark plugs at 120k miles found the plugs were OEM from the factory. Their gap was over twice as wide as the spec for the plug. Well after the plug change I never had the cold start issue again. Evidently, the large plug gap was not igniting the fuel efficiently when cold starting. This is also when the computer supplies a richer mixture to the cylinders. Between the bad plugs and richer mixture, it was enough to flood the engine many times on cold starts. It might be worth pulling a plug to check the gap if you haven't ever replaced them or haven't done so in a long time.

 

[tech7000]

I had a similar problem. The engine would flood many times when trying to cold start it. When it was warm it started and ran fine. I checked fuel pressure, changed the fuel filter etc. and nothing worked. Then I decided to change the spark plugs at 120k miles found the plugs were OEM from the factory. Their gap was over twice as wide as the spec for the plug. Well after the plug change I never had the cold start issue again. Evidently, the large plug gap was not igniting the fuel efficiently when cold starting. This is also when the computer supplies a richer mixture to the cylinders. Between the bad plugs and richer mixture, it was enough to flood the engine many times on cold starts. It might be worth pulling a plug to check the gap if you haven't ever replaced them or haven't done so in a long time.

I replaced the plugs last year with tripple platinum's as well as the coil pack so that should not be the issue. But thank you for your reply

 

[tech7000]

can you get fuel pressure at the rail?

only after getting it started - before that there is little or no fuel pressure. Once it's running it's ok

 

[J_C]

You turned the key to the run position (Not trying to start it yet) and at that point have no fuel pressure? If this is the case, your fuel pressure regulator is bad, or fuel pump itself is intermittent. Do you have a valve on the fuel rail to check pressure or are using a scan tool for the live data? With a scan tool I'd also check the coolant temp reading and the crankshaft position sensor (while cranking, of course).

 

[tech7000]

You turned the key to the run position (Not trying to start it yet) and at that point have no fuel pressure? If this is the case, your fuel pressure regulator is bad, or fuel pump itself is intermittent. Do you have a valve on the fuel rail to check pressure or are using a scan tool for the live data? With a scan tool I'd also check the coolant temp reading and the crankshaft position sensor (while cranking, of course).

When the engine is cold and I turn the key to the ON position there is no sound at all from the fuel pump. But once I use starting fluid to start it and warm it up, then turn off the engine and turn the key back on I can hear the fuel
pump and regulator click in and it starts again as long as i's warmed up. - I did replace the regulator - am going to get the coolant temp sensor later this eve and install that and see what happens. Might also order the crankshaft position sensor as well - I'll have a whole new fuel system here soon

 

[Fix4Dirt]

what happens if you turn it to run back to off back to run a few times? sometimes that wakes it up and can see if it has a bad leak valve whatever its called

 

[Pete Deering]

I have replaced the Throttle Body, fuel rail sensor, fuel pump regulator, MAF sensor, fuel filter, fuel pump relay in the fuse box, and the air filter. The engine cranks but will not start cold unless I use starting fluid. Once it starts it runs great, smooth, lots of power and no issues and I can drive for hours. When I stop for 15 - 20 minutes it will still start good - however when it cools down it fails to start again unless I use starting fluid., Acceleration is excellent and no hesitation or loss of power. Is there something else that can cause this issue ? Could the coolant temperature sensor or crank shaft position sensor cause this ? Any help would be greatly appreciated.

Did you scan it for codes?
Do you have a scanner that scan for coolant sensor temperature. Not the sensor for your gauge. The sensor that tell the PCM, if the engine cold or warm.
When that sensor fail the PCM does not know the amount of fuel, firing length.
On your car I don't know where it is.
What engine do they do you have?

 

[tech7000]

Did you scan it for codes?
Do you have a scanner that scan for coolant sensor temperature. Not the sensor for your gauge. The sensor that tell the PCM, if the engine cold or warm.
When that sensor fail the PCM does not know the amount of fuel, firing length.
On your car I don't know where it is.
What engine do they do you have?

I have a basic Actron scanner and cannot scan for specific component codes. The engine is a v6 4.0

 

[Pete Deering]

T

I have a basic Actron scanner and cannot scan for specific component codes. The engine is a v6 4.0.

2006 Ford Explorer

Testing

With the key in OFF position and the EHT sensor connector disconnected, measure the resistance between the sensor pins.

Normal resistance at normal operating temperature is approximately 2.80 k-ohms.

With the vehicle at normal operating temperature, the key in the OFF position and the ECT sensor connector disconnected, measure the resistance between the pins of the ECT sensor.

The resistance values should agree with the charts given.

With the ECT sensor connector still disconnected, the key in ON position, measure the voltage between the harness connector pins.
The voltage values should agree with the chart given above.

Identifying the ECT sensor pins and operating parameters—2005–07 4.0L (VIN E, K) SOHC engineClick to Enlarge

Ⓒ 2022 Chilton, an imprint of Cengage Learning

I have a basic Actron scanner and cannot scan for specific component codes. The engine is a v6 4.0

 

[410Fortune]

It maybe time for a new pump

 

[tech7000]

It maybe time for a new pump

I'm leaning towards that - ordered a pump just in case

 

[tech7000]

what happens if you turn it to run back to off back to run a few times? sometimes that wakes it up and can see if it has a bad leak valve whatever its called

Tried that a few times it worked and now nothing

 

[tech7000]

Update: I installed the new Crankshaft Position Sensor and after turning on the ignition and off I finally heard the pump click. It started then stalled 2 minutes later. It restarted right away though and I let it idle 10 minutes then jumped in and drove it about 5 mile, stopped and put gas in it and it started up right away. That was 4 hours ago. I just went out and it started up fast and strong. Idled for 5 minutes and off again. I'll see how it starts in the morning .

** After sitting over night it will not start once again. Now getting following codes: P01U202391 Fuel Rail Pressure Sensor A Circuit Range / Performance Pending
** P1235 Fuel Pump Driver Circuit Out Of Range
** U2023 Malfunction Received From External Node Non-MIL