Most of you probably don't know me as I have been away from this site for many years, but used to spend a great deal of time here back in the day.

Got a CEL back in July and my mech put the code reader on it. Told me it was likely the CPS, so I replaced it. No problems except for one time weeks later it threw another CEL but it coughed once, the light went out and all was fine until a couple of weeks ago when I had a crank but no start condition (with white smoke). The trouble shooting flow chart suggests that those conditions are indicative of a wiring harness issue or a bad CPS. The truck had been starting and running fine after that one recent incident (it eventually fired up after 20+ attempts spaced out over a couple of hours). As a precatuion I bought another new (OEM both times) CPS yesterday afternoon. Had a crank but no start situation this morning, so I just threw the new CPS in her and she fired right up.
The question, after this lengthy introduction, is simply this:
Has anyone else experienced a bad new CPS? I am just wondering if I am going to have to start inspecting/cleaning every electrical connection I can find in the harness.
Thanks in advance for any input.

 

I have only experienced what happens when it completely fails out of nowhere. When I replaced mine with an OEM one from Ford, I haven't had a single issue relating to it for about 6 months now.

My dad has had issues with older and newer ones though. He replaced his with one from O Rilies. It worked at first, but then started to have weird interference issues like his wiper blades would turn on when he used something else. Then, it would randomly stall out while he was driving to work. So he replaced it again with an OEM one and hasn't had an issue in a little over a year.
That was not an OEM one though. It is possible to get faulty parts from anywhere. I once went through 8 brake rotors and 3 calipers on my camaro, that was pretty exciting.

 

Thanks, man! I had electrical gremlins in my '82 F250 gasser back in the day. Never knew when it would quit dead. Open and slam the driver's door and would start right up and run for any number of miles. Eventually, that stopped working so I'd have to pop the hood and wriggle the wiring harness. Again, all would be fine for an indeterminate period of time. When that stopped working reliably, I began tackling electrical connections one at a time. Eventually, I must have found the culprit (because sometimes I actually wriggled the problematic one even though that wasn't the one I was disassembling, cleaning, and securely taping back together) becasue it never did it again until I sold it at 240 k miles.

 

Did you purchase the CPS directly from Ford or International? Part stores and internet packages do say "Original Ford OEM Part" and they were, however usually older versions of the part. The newest, available from Ford is dark gray in color with a purple o-ring.

 

I currently have one from RiffRaff that I've run, and currently use as a back up, and the other from Amazon. Both have the same part number, F4TZ12K073C, and sell for around $23.00. Hard to beat.



Motorcraft Cam Position Sensor CPS 94-03

 

What code(s) did you get?

 

Dealer part. Wouldn't start again on Monday morning, 250 miles from home.
Something electrical is going on.

 

Scan for codes again.

 

Wiggle wires at the CPS and see if it starts. Maybe have someone cranking on it while you move wires (carefully by the fan!!!).

But to answer your original question, yes! I have spoken with many, many customers that had gone through 5 or 6 Ford CPS before getting a good one. Fortunately for us we have only seen a couple bad from Ford.
Symptoms of bad CPS range from dying while driving, no start, poor running with white smoke, etc.
All new CPS are junk, but Ford and International have the highest quality junk.

 

Agreed, here is a good but simple article describing how the CPS functions. Needless to say it is the heartbeat of the engine. Without the proper pulses in no way is the PCM going to instruct the IDM to fire the injectors if it doesn't know where it's at in engine rotation.

7.3L Cam Position Sensor - Ford Diesel Performance Parts Blog

Awhile back in the old days the CPS was shimmed to provide the proper gap from end of CPS to camshaft rotating wheel, done at the factory and special tools required. Guess this technology is now lost. There are a few articles describing how to do this posted on here, somewhere.

To me it's amazing everything just works, most of the time ...

 

Thank you for your comment!