My 2003 V10 Excursion with 117,000 miles died 4 times at different stops. Started right up each time. Gas was below 1/4 tank. I had noticed this week that it has been missing occassionally, but tonight it would just die while stopped. I did have the overdrive "off" light flash one time. Could it be Idle control module, bad plugs, coil on plugs? I tried to get Advance to scan it but their scanner was broke. I just replaced the fuel pump last year. When it went it never started back up.

 

OD light flashing means a trans code. There are some tranny issue that will cause stalling like that. You'll need to get those codes scanned and go from there. Most code readers do not read trans codes however.

 

check the battery terminals and make sure they are tight. Same happened to me a week after I installed a new battery

 

Fuel filter good?

 

I had the OD light flashing a couple months ago. Turned out the speed sensor on top of the differential was dirty OR the connection to it corroded.
I unplugged the sensor and unscrewed the bolt holding it in. Took it out and cleaned the sensor. There was some oil on it but nothing else. Haven't had the code since.
Only symptom I had was incredibly hard shifts. Shifts great since I cleaned it.
A simple and quick possible fix you might try first. 5 minutes.

 

I got the codes checked today and P0722 - Output Shaft Speed Sensor Circuit No Signal and P0720 - Output Shaft Speed Sensor Circuit. Does anyone have a picture of where the OSS Sensor is? I think it might just be dirty. I am going to try cleaning it first. The only thing I have now is a miss. Check engine light went out today but it still misses. It has not died since I put gas in it. The fuel filter was changed when the pump was replaced.

 

You may want to change the filter again, possibly picking up sediment from the tank when running low on fuel. As far as the miss check the vacuum hose under the throttle body to PCV for cracks, maybe get a new cop and try it in different cylinders. EXv10 also has a thread about how to fix the water leaking into cops in the tech section.

 

It's on top of the rear differential. Easy to spot. I got the same code a few months ago. Cleaned it and it's been great since.

 

Is there any way to test which COP may be causing the problem or a code that tells which cylinder needs looked at? Do you have to take the fuel rail loose to change the COP's?

 

No, the fuel rail does not need to come off.
COP is held down with one bolt.
IF it has issues idling, you can try disconnecting/reconnecting one COP at a time. Do this for each COP. Each time you should hear a drop in rpm. If there is no change when you unplug it, you might have found a bad COP.
Be careful with the connectors. They get brittle and the clips that hold them in place can break easily. I've also heard people having issues with the bolts breaking off.

Did you clean that rear sensor first ? Very easy to do and free.

 

No, it has been raining and I have not been able to get under it to clean it up. I am considering changing all the plugs though. It has over 118,000 miles and I do not think the plugs have ever been changed since I have had it anyway. I was reading all the horror stories about broken insulators, pulled threads, etc... and I was a little scared to try it then I saw that the Excursion did not have the plugs that broke off. I will try the COP testing method first ad see if I can isolate any bad cylinders. Thanks.

 

Make sure to use a torque wrench when you do the plugs.
Read on here and in the 6.8l section. Not enough torque and the plugs walk out, too much torque and you risk stripping the threads.

 

When you unplug the COP with the engine running do you have to worry about getting shocked like you do with plug wires?

 

You only unplug the little connector TO the COP. Not the COP itself.
No you won't get shocked.

 

Thanks for the info.