Okay, this is my first post on this site so please overlook my ignorance if this is not the correct format for my question(s).

First, I have a96 Ford Explorer XLT with a 4.0L engine with 147,450 miles on it. About a couple of weeks ago I was going to Walmart and started my vehicle and it turned over and started just like it should. Yet, when I left Walmart and got into my vehicle to go, my vehicle turned over (strongly I might add) but would not start. For a minute I thought that I might have water in my gas. So, I tried cranking the engine once again. This time I pumped the gas. The start-up this time had a rough idle but the engine did finally started. Then I went to a local Auto supply store and purchased some a bottle of injector/gas/carb cleaner. My vehicle ran pretty good after that but has now begun doing the same thing.
My vehicle starts good when first cranked. But when I get to where I am going and attempt to start my engine, the engine turns over good . . . it just won't crank. That is, until I begin pumping the gas pedal. And as I said, the the engine cranks but it's cranks with a rough idle. Then finally smooth's out.
I checked the ignition coil and fire is present on all six cylinders. I then though about the condition of the plugs since they haven't been changed in about 4 years. I also thought about the oxygen sensors.

Does anyone have any ideas what could be causing this problem?

 

I would replace the fuel filter, first, than check make sure EGR is not stuck open, Then a throttle body service, using a soft toothbrush and some gm top engine cleaner, you can remove the IAC and soak that with the GM top engine cleaner, just soak it couple hours, sound like your not getting enough air in at startup, either from the IAC sticking or carbon around the throttle blades.

 

David 7.3;

Okay, I may appear just a tad ignorant since it's been sometime since I have messed with an engine, but exactly what is the IAC? I have a Haynes Repair Manual and subscribe to AllDataDIY and have found nothing with those initials. I found the location of the Mass Air Flow (MAP) sensor and the location of the Intake Air Temperature (IAP) sensor but none of the diagrams show an IAC sensor.

I took the air filter out and cleaned it with compressed air. I also removed the MAP sensor and as soon as I removed it from the housing the engine started to idle roughly. When I plugged it back in the idle was normal. I also removed and checked the IAP sensor with the engine running and nothing happened when I did this.

About eight months ago my fuel pump went south on me and I had to have it replaced. AAA did the repairs since I didn't have a lift available. Anyway, they (according to the billing statement) replaced the fuel filter. Can a fuel filter go bad in that short of time? Besides, after the engine is running and I'm driving, it runs as normal as can be. And as I said, the only time I have issues is when I go somewhere, turn the engine off. Then when I return and start the engine, the engine turns over as it should but just will not start as it starts when cold. This is when I pump the pedal several times while the engine is turning over and it starts. It starts rough, but after a minute or so the idle smooths out.

 

Put this in the Explorer forums and more people will see it and you will get more help.

 

Chugalug;
I losted. I have typed in Explorer in the search block and all I get is a list of threads on a variety of subjects. Nothing in particular pertaining to Explorers.
Anyway, I finally found the IAC controller located on the air chamber throttle housing and replaced it. After replacing the IAC controller, my Explorer worked great for about two or three weeks. Then last Friday (Oct. 17) I was going to the store. The engine cranked great and started just like it had multiple times before after changing out the IAC. However, after letting the engine warm up, I put my truck in gear and the engine immediately died. I then attempted to start the engine again and it was just like before changing out the IAC. The engine would turn over as it should but WOULD NOT start. I would then press the gas pedal several times and the engine would start but idled rough for a moment or two. Yet each time I attempted to move the shifter into "Drive," the engine would die.
Some time ago on another vehicle I had some issues with the catalytic converter. That car would not run to say its life. Every time I came to a stop, the engine would die so I replaced the catalytic converter and the vehicle ran great.
Do you-- or anyone else for that matter --think the problem could be with one or more of the oxygen sensors or the catalytic converter.
In the short of it: When the engine is cranked (when cold) the engine turns over very strong. Yet after allowing the engine warm for some time, then moving the shifter to "Drive," the engine immediately dies.
I am at a loss. I have checked the IAC controller, the throttle plate; I know the injectors have gas flowing to them, the ignition coil has a good spark, the air filter is clean, the same for the MAP sensor. ????????????????????????