2004 explorer 4.0 hard start

[mmasire88]

Having some issues here lately as the weather gets colder with my Explorer having a hard time starting, long cranks, not firing right away like it use to. Went out this evening and it took me a good 3-4 minutes of cranking to FINALLY get it to start, bit of a rough idle for a few seconds and than idles and runs perfect. Only seems to have a hard time starting after sitting until it's cold. Once it's warm it fires right back up. Any ideas? Also, there are no cel's.

 

[imp]

Sounds exactly like the symptoms of a carburetor car not starting when it's very cold, and the choke is not closing to richen the starting mixture.

Your computer needs to know that it's cold; it gets that info from a sensor stuck into the coolant in the engine. It's called the "Engine Coolant Temperature" (ECT) sensor.

Odds are good that if you replace it, she'll start good again when cold, run better initially, once it starts, too. ECT sensors are not very expensive. imp

 

[IPcamper]

You might want to check your fuel pressure. I just replaced the fuel pump in my Ex because the check valve failed. The fuel would drain back to the tank and it would take a long cranking to build pressure before it would start. Restarts after a short shut down were no problem, but if it sat for an hour or two, it was a problem. A trick, that someone else on this forum suggested, is to to turn the key to ON, wait 2 seconds, turn it off, repeat two more times and then crank the engine. This will run the fuel pump longer and build pressure before starting.

You might also want to replace the fuel filter, If it has become clogged, that might cause some problems as well.

 

[King-Explora]

4.0 hard start fix

Mine would do "EXACTLY" what you described, both last year and again this year as it got cold. Open up your intake pipe and see if your throttle body has a bunch of black carbon cake. clean it with some starting fluid on a rag and it should take care of it. the carbon gunk causes the throttle to stick when it gets cold. This might help you

 

[mmasire88]

IPcamper, this was my initial thought, that perhaps fuel was draining back into the gas tank, so I have been for the past few weeks cycling the key on and off before starting but it doesn't seem to make a difference.

King-Explora, I just finished replacing my motor a few months ago and before installation I went through and cleaned the throttle body out very well, I can't imagine it's junked up again.

I went out this evening to head to the store it was roughly...35F degrees outside, and it fired right up without hesitation. Seems to be an intermittent issue.