This is my 1st time posting on a forum. Please be "gentle"!
My F250 Super Duty-7.3L-Crew Cab has 242,000 miles. The truck starts & runs perfectly & has a consistent fuel economy of 17.6 mpg. It has been trouble free until its' "phantom" problem began over a year ago. The problem ONLY occurs in the rain or periods of "heavy mist".
When moving 5 m/p/h on the side streets, or 85 m/p/h on the freeway, without warning, the engine will die. Most of the time, it starts back up "by itself" after 1 or 2 seconds with NO intervention on my part. Sometimes while on the freeway, it will die while I am moving at 60 to 80 mph & as I am coasting, I put the shifter in neutral & start it back up immediately. Most of the time, however, it will start back up "by itself" before I can even put it into neutral.
At the beginning of a major "drought", I took my truck to a well respected Ford Diesel Specialist who used to be with Ford Motor Company before he went on his own. He had my truck for 45 days, trying to duplicate the problem. He could not get the truck to fail. He even had his helper "hose down" the engine compartment for 20 minutes while he tried to get it to fail, with no issues. Finally, on the only day of rain we had, while the truck "was in his covered bay", the truck began to die several times over the next few hours. He said that while his engine code tester was hooked up, NO CODES were ever generated!
He replaced the ECM; CPS; TPS; MAP sensors. Also 2 wiring harness connections. There is NO WATER leaking into the passenger compartment, so no possible computer issues due to that.
At this point, I am willing to accept any suggestions that anyone has.
I hope there is a genius out there in "Forum Land" who may have had a similar problem resolved!

 

This has been reported by several people. Most often, changing the cam position sensor to an OEM Ford or Navistar part solves the problem, as long as it isn't only occurring when the wiper are on. If it only happens when the wipers are on, try relocating the wiper motor ground to a different location. It seems the shared ground has caused interference with the sensor signal for some people.

 

X2 , I was going to say wiper conflict with the cam signal . From what I have read .....

 

Welcome to the forum. Who was the well respected diesel specialist? 45 days is an unbelievably long time to keep the truck, and hosing down the motor sounds like something a rookie would do.

Do you know where the CPS is? Can you tell us what brand it is? Several aftermarket CPS's have had issues that make the truck stall when the wipers are running, so take a drive when it's not raining with the wipers running, anywhere from full to intermittent.

Luckily for you there are a few forum members down in your area who may see this and may offer to volunteer to meet up and take a look at it with you. There are also a couple or respected Diesel mechanics down in your area. David at Diesel Innovations or Dorian at Powerstroke Enginuities should be able to figure this out for you

 

My money is on relocating the ground and eliminating the interference and of course checking to make sure you know which CPS is in there.....

Which reminds me, I should figure out which one I have as well....

 

Welcome!

As others mentioned, it sounds like a typical CPS interference. Here is a quick video on the matter. I would suggest trying a dry run with wipers, then replace with an OEM part. Riffraff has them cheap, around $20.