HI all,
I have a 2000 Excursion with the V10 engine, for the past 4 months been battling a no start issue with my truck, it will crank strong but wont start, it will start and run say first thing in the morning but if you drive it around as little as around the block and shut it off it wont start just sits there and cranks. sometimes we have to wait a few minutes sometimes a few days, I get good fuel pressure at the rail, I started recently unhooking the battery every night and that fixed it to where it would start up in the morning but after running a while it wont start, when it is in its no start mode my scan tool can not read the computer, so I took it into a shop and they determined it was the computer but they can not flash it so I bought a unprogrammed one because they are cheaper and found a shop that can program it that happened yesterday, drove it home shut it off, it started right up several times so I thought gtg but wife gets ready to go to work this morning after sitting for about 20hours and the truck wouldn't start but after about 5 minutes of her trying it finally did, so I am at a lost please help!! I am thinking crankshaft positioning sensor????

 

Try checking the pcm relay swap it with the horn one ad give it a try

 

I recently had this same problem. Random instances of cranking but not starting. The X did not throw any codes. Once I even had it towed to the dealer but it was working again after it was dropped off.


Finally if failed while they had it. It was the crankshaft position sensor and that fixed it. The part is not expensive and pretty easy to get to. Wish I knew it at the time so I could have saved some money.

 

It's also possible that it is the key itself. Try another key.

 

Would a key fail randomly? It is worth trying another key but I would think in would always be good or always fail!

 

Had a similar issue last week with mine. Thought it might be a loose battery terminal so I cleaned and lubed the battery terminals and haven't had the issue since.

 

No, it is NOT possible for a key to stop the engine once it's running.

Try the PCM Relay FIRST, it's the most common failure.

 

Thanks for the inputs, sorry its been awhile since I replied, I did switch the PCM Relay but that relay still worked in the other spot(I don't remember what I took it from) but its now seem to fix itself some what its funny because it works perfectly fine with the wife she has yet have it not start for her but a couple of time I will go out in the morning try to start it and it wont start but if I try it again right away its starts right up unlike before where it might take like 20 min to start even if it would. so right now at this point we are just going with it but if it becomes a bigger problem I will replace the Craftshaft Positioning switch.

 

Never said it was ?? The OP is "WON'T START" & it is possible for the chip in the key to create a "NO START" condition.

 

Glad it seems to be working again.....but my guess is it will reoccur. Besides the random no start caused by the crankshaft position sensor some time ago I had a similar problem caused by an unplugged PCV valve. A major vacuum leak such as an unplugged PCV valve is easy to check and cheap to fix.


Good luck!