Help me please. I have a 2000 350 w/ 7.3 PSD. I have a Tymar intake and a Predator usually set at 60hp. Otherwise stock. A few days ago, I was driving about 40 mph and the SES light came on and all the power went out of the enginge, but it did not die. After about 5-10 seconds, the power was back and the light went out. Everything was fine for a few days. Then we hit a cold snap and (around -15 overnight two nights in a row). It started cutting out pretty regulary at that point. I put in some white bottle Deisel Kleen thinking it may be deisel gelling. We got back into the 30's and I figued any gelling would be gone. Still have the same problem. Changed the fuel filter and it ran fine for about 10 minutes.

It acts like a fuel related issue, as it will rev ok above 2000 rpms and then run very rough at idle. While trying to get it home, it would barely be going (20 mph) and then kick in full power w/ no light. Then it would run with no power again. I used the Predator to check fault codes and there are none. I don't know what else to do. I swore that the next time I had a few hundred dollar repair bill I would get rid of the thing, which I hate to do because I love the truck. Just can't sfford to keep throwing money at it. HELP me save my truck. Thanks.

 

Sounds to me like either you have an air leak on the suction side of your fuel pump and are injesting more air than your filter/water/air separator assembly can handle, or the high-pressure oil regulator valve is clogged/sticky.

Just some immediate thoughts based on the symptoms.

Your engine's lube oil level is at full, isn't it? It can't get too low before things like this appear.

Pop

 

wondering if valve cover wiring is acting up ... does it seem like one side of the engine in particular is goofy or is it throughout the engine?

 

It sounds exactly like what happened when my UVH's (under valve-cover harness) started to unplug themselves. You pull the valve covers off and put on some little cheap plastic wedges from Ford. It's kind of a pain to pull the covers so get some new glow plugs to put in while you're in there.

 

Alright - two out of three think it is the valve cover wiring. I have not looked at it yet, but I assume that it controls the injectors in addition to the glow plugs. I further assume that the problem with the wiring harness is that it is effecting the injectors. The problem is not a cold run exclusive problem.

Are these correct assumptions? Would the Predator's engine monitoring function pick up on the injector problem?

 

Might also be the predator doing it.

 

Your assumptions are right on. Does it feel like it's "missing" on several cylinders? Kind of like if you yanked half your spark plug wires off a gasser?

 

Kind of like bad gas (on a gasser) or sticking float valve on a carb. The reason I compare it to bad gas is that it does not alway miss. It will be idleing just fine then start missing. I'll rev the engine to ~2000 rpm and it will clear up (and the SES light will go out). Then it will idle fine for awhile. Then it will start missing again. While driving, it will drive fine, then hesitate, then accelerate, then totally bog down and barely run, then accellerate. I have restored the original backup from the Predator and it still does it.

One of the biggest problems is that as I try different things to fix the problem, it will clear up for a day and lull me into thinking I fixed it. Then it will start hesitating 2 or 3 miles from home and I'll barely get home. That reminds me -- one of the times it started its trick, I had to climb a short but steep hill. I had the pedal floored and it climbed the hill at 15 mph (45 mph zone). It was smoking like crazy. Gives me the impression that it is over-fueling. That seems like it would contradict a wiring harness problem in which one bank of cylinders is not injecting.

Update on the wiring harness:
This afternoon I pulled the driver's side valve cover (easy side) and checked the wiring harness connector. How cheezy it that? It is exposed to heat and oil and relies on a little plastic clip to hold together. Ford should be ashamed. It seemed loose, but I don't know if that was the problem. The dealer knew nothing about the "wedges" and I'm not sure I want a wedge loose in my engine. Tried to find a zip-tie solution, but ran out of time and just clipped it back and reassembled. So far so good. Drove it about 6 miles on two trips with no problem. As I stated earlier, though, I am still waiting for it to act up again. We'll see. I'll keep you posted and appreciate all your help.