2000 F250 7.3 with manual trans

While driving, under varying conditions (loaded, cruise, off throttle, etc) there is a sudden loss of power in the engine. It does not stall. Engine goes to idle. Wait to start, service engine soon, and water in fuel lights illuminate, and all the relays in the dash click off. Feels like the jerk you get when you have a faulty crank position sensor, but theres no code for it and Ive never had a CKP turn off relays and illuminate lights. There are some codes. Cam sensor codes, exhaust pressure codes, intake air heater codes, and fuel pump circuit codes.

Replaced the fuel pump relay and inertia switch, PCM relay, IDM relay, exhaust pressure sensor, and tried several cam sensors. Found moisture on the PCM and IDM connectors so I dried and greased them. Opened the PCM to check for internal damage, none found. Cleaned and greased all connectors in drivers fender well area. Theres no obvious signs of burned wires or chaffing, but everythings caked with crap so...

So Im leaving this one to you fine people. Has anyone had this issue before? Are there any commonly fried or chaffed wires I should look for? Can I test the PCM and IDM without a breakout box? Im really in a jam here, any help at all is very much appreciated.

 

If I had to guess, you have an UVHC coming loose. Can you tell us what codes exactly you are getting?

 

Welcome to FTE. First I'm curios to know which CPS you are using? We've heard of many issues with aftermarket units, and since you are getting a cam code, you need to make sure you have a Ford CPS installed.

Can you tell us which specific codes you have and what mods you've got on the truck? Also, what are you using to pull the codes? You seem to have a good grasp of the 7.3, if I told you to check the wiring around the 42 pin connector, the harness over the front drivers shock, or the wiring in the steering column, would that make sense, or do you need some additional input on the 42 pin connector or how to remove the steering column?

 

Can you explain UVHC?

Codes are/were PO542 intake air heater circuit A low, PO476 exhaust pressure control valve performance, cam position sensor circuit malfunction, and fuel pump secondary circuit low

 

This is the first time Ive worked on this truck. Its not mine. Im a tech at a repair shop in Connecticut. Ive tried two aftermarket CMPs and the "correct" Ford grey/silver CMP. As far as the 42 pin connector goes, I wouldnt know where it is by number, but tell me where it is and what it looks like and I can find it.

 

Leaky windshield, water on the GEM?
That water on the PCM plug had to come from somewhere.

 

As far as codes go, theres nothing in there now on continuous memory. Im using the Solus Pro. If I do a KOER test, I get the PO542 and the PO476

 

I thought Id find water in the modules but the PCM internally looks ok. No green areas, or burns

 

Dan, that's what it sounds like to get that much activity when it hiccups.

 

The GEM is the fuse panel, it powers everything on the truck and if you have a windshield leak, it drips right onto that thing.
This is a semi-common thing with these trucks, you need to keep close tabs on how well the windshield is sealed.

Yeah, it really sounds to me like the power is getting interrupted for a little bit and then it comes back.
Might even be a relay that is failing.

 

I sometimes respond slow so if any of this has already been posted, ignore it.

UVCH = Under Valve Cover Harness. Doesn't sound like the issue to me, but a common fault on this model 7.3 is the connector underneath the valve cover comes loose, which will cause one or more injectors on this side not to fire (sometimes intermittently).

The 42 pin connector is the square box with a bolt in the middle of it on top of the drivers side valve cover. The harness has red striped tape around it. This is the wiring between the IDM and injectors (among other things) and a chaffed wire below the connector against the valve cover, or behind the connector against the support bracket can cause a short to ground which makes the PCM reset. The reset causes the WTS, CEL, & WIF light to flash. This will typically only throw a RAM code, so info about mods are important. Have you checked the PCM to see if there is a chip installed? A loose chip can do the same thing.

You also mentioned a wet PCM & IDM connector. As I'm sure you know, water and electronics don't play well together. I'd check and grease the CPS connector too to be on the safe side. You mentioned checking the internals on the PCM, but what about the IDM? Did you pull the fender liner and find water in the connection at the IDM, or are you referring to a different connector? I'd be checking the IDM internals, or at least shaking it listening for water.

 

Ok Ill have a look at the GEM. Any other ideas?

 

As far as I can tell, there are no mods. This PCM is not chipped. The 42 pin connector seems like a likely culprit.

As far as electronics go, I grease EVERY connector before it gets snapped. Im just that way. The PCM was split open to check for intrusion, but the IDM seems to have sealer around it (looks almost like a thick bead of grey permatex), that I didnt want to disturb. Is that from the factory or maybe its been opened before? I handled the IDM quite a bit, theres no liquid sound that I could here.

The moisture in those connectors wasnt much at all. Not to say it didnt concern me, but the amount was so minute that it was barely visible.

 

There shouldn't be any moisture in there at all. Period.

 

Are the only codes you're getting coming from a KOER test? Any stored codes without running either a KOEO or KOER test? It seems odd you're not getting any PCM or IDM codes with the cut out issues. Between the water and other descriptions, this really surprises me, but I've been surprised before.

My advice is 1) Pay attention to Dan. He's a real mechanic, while I just play one on the internet. and 2) Change the CPS again until you no longer get any CPS codes. A bad or intermittent CPS signal will cause the engine to shut down (either momentarily or longer). We need to eliminate the CPS codes before moving on.

I had a short near the 42 pin connector and while I got the flashing lights, I never got a CPS code.