Background: purchased F250 7.3l used in 2/05. Had 40,000 miles on it. Ran great until 3/05, when towing over the Grapevine during rain it coughed and caught itself a couple of times, but it also died outright. Restarted immediatly. I thought I had a bad trailer plug as the cap that holds the plug in was broken. Ran great all year, no rain here in SoCal, until the other day. Driving down the Freeway, doing 70, in rain, the truck just quit, no warning, nothing, about 4 times within a 10 mile drive. It quit raining, the truck runs fine. It rained again last Thurs. Same stuff, drive around in the rain, it quits, but I can start it right up again. Please note that the electric stays on,, i.e. the wipers wipe, the radio plays. From what I've gathered on this forum it might be the CPS, but the again does anyone have any other thoughts.

Thanks

 

Sounds like classic CPS problems to me (except for the rain part). Maybe if you unplug your CPS, clean the plug real good, and then seal the plug good when you put it back together. But I would replace the CPS and then seal the new one at the plug.
Joe

p.s. Welcome to the forum.

 

Uh-huh, three letters C-P-S.

I've read that if certain CPSs if they aren't sealed properly or are on their way out, almost any amount of moisture will bring your truck to a stop. It's an easy fix, but it'll cost you a pretty penny. Head over to your local International dealership and they'll get you a CPS way cheaper than the dealership would think of givng it to you for. It's also a good idea to get 2 if you're buying it, you never know when a CPS will give you a problem.

 

Welcome to FTE squaredancer.

Everybody needs a spare cam sensor, so I won't tell you not to buy one. But for your problem I'm not so sure that's the fix. I think that the weatherpack connector for the sensor is letting water past and messing with the signal, or water is getting into the IDM. I think you need to get in there and check the seals on the connectors before you start throwing parts at it.

Maybe even test it. Shoot a water hose at the cam sensor with the engine running, see if you can force it to quit.

 

It's the CPS. Bought mine in June. Ran fine until I took a long trip in July. "Coughed" during intermittent rain, and though that was the problem. Just got worse over the months. "Coughed" repeatedly and then started to die while at idle at stoplights, etc.. Had nothing to do with rain or wet, but maybe that is the precursor to an overall CPS failure.........the "Moisture" factor.....Changed it in Dec, and NO problems since....

 

p.s. It's a 2000 F250 4X4 psd.......I also had 40,000 miles on the OD when I purchased it.........good luck.....

 

Good info cmpd1781, thanks.

 

Well Squaredancer, your problem is the exact same as mine last September and the reason I joined FTE. I replaced the CPS and problem was solved. I too live in SoCal and really haven't had much chance to test for results, but to this date the problem seems to have been solved. If it does continue after replacing the CPS, clean and apply dielectric compound to the IDM connections. The IDM is really in a area that can get wet easily and cause problems.

Good luck
Wings

 

Just a follow-up. I did replace the CPS. It may be my imagination but the truck seems to run smoother (just like a car when it just got washed and waxed). Drove over the Grapevine in real nasty weather this past week end with no problems. i thank you all for your kind words and advice.
BTW, I visually inspected the old CPS and noticed corrosion on the right most connector pin (as you're looking at the unit with the metal barb toward and down to you. In the electronics industry we'd find that when we connected two dissimilar metals, especially if one of them was a real cheap metal. I plan to clean it off and use it as an emergency back-up.

 

You think that if you put di-electric grease it might help?

 

I'd want to scrape all that corrosion off first, then put the dielectric grease on it.

 

I meant on the new one so it doesn't rust up. Didn't someone said they were gold plated now or something?

 

Could the long problem with the CPS be just a poor design of the plug and not the CPS itself? I would think that di-electric grease would make a big difference, but what about a spray on coating the protect from water, and many other road grime things that could interupt the signal?

 

Bill,

I've been thinking about that for a while now. There are some CPS's that just "go out completely" and others that are intermittant. I have previously asked the question if just a disconnect and re-connect would make just as much difference as a change-out on one that was intermittant.

If I were going to try to improve the reliability of mine, I'd use a very, VERY small amount of silver-paste conductive grease on each individual connection to insure a good, low-impedence connection. Then, use dilectric grease to waterproof the connector body, keeping it away from the three individual contacts.

Pop

 

Not only does everyone need an extra CPS but print off the instructions if you have never done one before and keep it in your glove box. At least if your on the road you will know what has to be done and have something to follow.