2004 4.6 134,000 miles. Thursday night My fiancee calls after work and the explorer won't start. I take the jump pack,jump it easily. Get it home and clean the battery cables. Turns over plenty fast and starts right up even first start of the morning. Now the problem she has and I can't get it to repeat when I drive it is that the engine will occasionally die at stop signs and start right back up. I have checked voltage in case it was the alternator or battery. In the morning before the engine is started, the volts are at 12.8 on the battery. With the engine running headlights on,a/c and fan on full blast,it shows 14 volts. I get 13.8 volts with everything off and engine idling. So I am thinking the problem isn't voltage related. I pulled codes,no codes in the computer. Engine Idles smooth as ever,no sputtering or misfiring. I am really at a loss and don't want to start throwing parts at it. Thanks for any suggestions!!

 

I know you've checked the voltages and it seems everything is fine, but check the age of the battery. If it's 3 years old or older, you should consider replacing it. I've read about and personally experienced symptoms not all that unlike what your fiancee reports due to an old battery that seemed to load test as acceptable.

In my wife's 2002 Lincoln LS the car would stall as she shifted from Reverse to Drive at the end of our driveway in the morning. Her car would start back up and usually be fine the rest of the day. It was only after the car sat in the garage overnight. The battery load tested just fine, the charging system worked fine, there were no diagnostic codes, the battery connections were clean and tight, and the engine idled and ran fine. After about a week of getting no where on troubleshooting, I changed out the battery for a new one. The battery was just over 3 years old. The stalling issue never returned as soon as the battery was replaced with no other changes.

The only thing I could speculate to be the reason was that the load on the battery after starting the engine and then pressing on the brake pedal to shift from Reverse to Drive was enough to cause the charging system voltage to drop in to the "gray area" for the ECM and the engine would stall.

-Rod