Ok, I am baffled! I have a 2003 F-250SD. Great truck, love her to death! There is one exception. She likes to shut off for no apparent reason. I travel at highway speeds, she shuts off. I travel in town, she shuts off. Cold or hot, cruse control or not, she likes to shut off. I can not duplicate the conditions that will make it shut off. Does not appear electrical, more like fuel. Filter has been replaced, plenty of pressure. Had it in our very trusted mechanic shop, and the only thing he could find is a slight fluctuation in the fuel pump relay, but he could not get it to duplicate the issue either. He stated the relay is on the back of and part of the fuse pannel.

Any ideas on why it would shut off? Again, not electrical, I do not get all the dash lights, just like there is immediate loss of fuel. I pull over, put her in park and she mostly starts right up.

I am basically loosing confidence in her, but I am very attached and do not want to replace the truck.

 

if its a 7.3 diesel you might need a new cmp sensor.

 

It is a 5.4L with just over 80k miles. Did it again last night. I got off the freeway with no issues, drove 2 blocks. I did notice that I had to turn the key completely off and then on again before it would re-start.

 

Bad cam or crank sensor perhaps?

 

I am somewhat savy, is this something I can change?

 

The cam sensor in in the front cover near one of the heads. The crank sensor should be down at the bottom of the block near the harmonic balancer I believe.

Not hard to change I don't think. Have you checked for stored codes in the computer?