Yes, I have a 96 Explorer XLT 6-cyl 4.0L -245 engine. About a month or so ago I was headed to my local Wal-Mart. The engine (cold of course) cranked and started just as it should. However, when I left Wal-Mart (about 30-minutes later) and started my truck, the engine turned over strong but would not start.
A reply to my post by David 7.3 said I should check my fuel filter or the IAC valve. I figured since I just had the fuel pump replaced by AAA along with a fuel filter (according to the billing statement), I looked at the IAC valve.
I changed out the IAC valve and my truck ran perfectly for about three weeks. Cranked strong and started just great, even after driving it for 30 to 40 minutes. So, I just figured this was the cause of the initial cranking problem.
Well, the very same symptoms started again. When the engine was cold it would crank strong and start even though th idle was higher than normal. Yet even after engine warmed up, the idle never really dropped to the normal level. But this time when I would pull the gear shift to Drive, the engine would immediately stall.
After further investigation, I checked the MAF sensor. Disconnecting the connector to the MAF, I started the engine. The engine started. I then attempted to pull the shifter into Drive. The engine did not stall and I was able to drive it around the block. So, I decided it was a bad MAF sensor.
Installing the new MAF sensor, the engine cranked and started. I allowed the engine to warm up to normal operating temp. Drove the truck around the neighborhood and returned home. Turned the engine off and attempted to start the engine again. No go! The same identical starting problems happened as before.
Reading the manual, the instructions said something about checking the MAF relays before changing out the MAF sensor. I have the AllDataDIY
program and looked up MAF relays but wasn't able to find anything.
Does anyone out there in FORD world have any idea what the problem could be?
Could the EGR valve possibly have any involvement? And if so, I have been driving around for three or four years now with an EGR valve "Check Engine" light DTC code and haven't experienced any problems.

 

Since unplugging the MAF allowed the engine to start, that was actually an indication that the MAF was working.... Typically if you unplug the MAF and it has no change you likely have a bad MAF.

In your case, since unplugging the MAF seemed to mask the issue, that's a good sign that you have unmetered air getting in to the intake stream. My suggestion would be to focus on searching for a vacuum leak.

What is the code number that you've neglected for 3 or 4 years? Is it defined as something related to the EGR position? Differential Pressure Feedback EGR (DPFE) sensors for this vintage of Ford is a fairly common issue and can cause symptoms like a vacuum leak.

Your V6 might also have the PCV elbow that is know to crack and create a vacuum leak. That would be worth inspecting as well.

-Rod