I have an early 99 F-350 with 268K miles. It is bone stock right down to the factory exhaust. A couple months ago I started have a rough idle and surging while driving problem. I never got a check engine light but I borrowed a scan tool from a friend and pulled the following codes: P1690 (wastegate solenoid), P0381 (glow plug circuit malfunction), P0269 Cylinder 3 Contribution/Balance Fault, and P0284 Cylinder 8 Contribution/Balance Fault.
I did some research and everything I read said it was most likely the CPS. So I changed the CPS. The truck ran fine for for a few days but then it started acting up again occasionally. I noticed that most of the time when it acted up was at start up when the engine was cold and I also figured out that if I shut the truck off and re-started it (sometimes I had to do it 2 or 3 times) it would clear up and run normal. A buddy of mine that has a 2000 F-250 said he had a similar problem with his truck and it ended up being the ICP sensor. We switched his ICP with mine and I changed my oil at the same time (because it was due for an oil change). My truck ran flawless for over 2-weeks (over 200 miles) so I put a new ICP in my truck. Note: my buddy did not experience any problems with his truck with my ICP
in it. I've put about 700 miles on the new IPR and the truck has started to act up again. Once again shutting the truck off & re-starting it will clear it up and still no check engine light. I took it to a local “diesel specialty shop” while it was running rough and they hooked it to their scanner and got P1280 (Inj. Control Pressure Low), P1690 (Wastegate Solenoid Fault), P0381 (Glow Plug Indicator), P0269 Cylinder 3 Contribution / Balance Fault, and P0284 Cylinder 8 Contribution / Balance Fault.
They never did anything other than hook it to a machine & check the codes but their diagnosis is my High Pressure Oil Pump is going bad and my #3 and #8 injectors are going bad. They recommended I let them replace all 8 injectors and the High Pressure Oil Pump.
The problem I have is they can't give me a REASONABLE explanation as to why re-starting the truck a few times clears up the problem.

 

When you start it cold, is there a misfire too? Does the misfire go away and cause what seems like a sudden gain in power?

Cylinders 3 and 8 often fail CCT with a cam position sensor other than the original, black, OEM CPS, so I wouldn't go jumping in to replacing all of the injectors just yet, especially based on the CCT codes. However, if your answer to my questions above are both yes, that can be an indication of worn injectors.

HPO pumps do fail, but it's relatively rare. If the shop you took it to can't justify their recommendations with a solid explanation, they're probably just throwing parts (and your money) at the problem, and haven't bothered to do any diagnosis beyond reading the codes.

 

Sometimes it's just a slight miss like a have a cylinder that's not firing 100%. When it does that I can drive it down the road and I get a surging but it has plenty of power and it might even come out of it while driving. Other times it runs so rough that it shakes the whole truck like it has at least 2 dead cylinders. When it does that if I try to drive it the truck chugs & jerks real bad (I'm talking whiplash) and barely has enough power to pull itself down the road.

 

Does it seem worse and last longer when it's colder outside, and not as bad on a warmer day? Do you have a scan tool that can run an injector buzz test?

 

30 degrees or 80 degrees, the outside temp doesn't seem to matter. When I had my friends scan tool it passed the injector buzz test. And the diesel shop said it passed the injector buzz test.

 

This is starting to sound like a short on a wire or the UVCH to me. It could certainly be a couple of things layered on top of one another, but I think you have to start wiggling some wires, and harnesses while the truck is running and see what you get.

 

I've wiggled every wire I could find trying to make it run bad when it was running fine and I've wiggled the wires while it was running bad to see if I could get it clear up. No luck either way. I was told by the prev owner that he was sure he had the wedges put in the harness under the valve cover but I have not pulled the cover YET to double check them.

 

When you do pull the valve covers, do it with the engine cold. Start the engine and watch the oil spouts on the injectors. Any with reduced or no oil discharge are an indication of worn poppet valve seats, especially if they suddenly start flowing normally as the engine comes up to temperature.

 

I didn't know that, thank you!
That's 1 more reason to pull the valve covers... which I'm not looking forward to.

 

The first time you pull them can be frustrating, but when you're done you'll realize it really wasn't as bad as you thought it would be. Do yourself a favor and get a 13mm flex socket like this one. It makes it much easier to get the back bolts and the ones next to the HVAC box on the right side. Double check the wiring connections at the inside and outside of the valve cover gaskets before you start the engine just to reduce the possibility that it is actually a wiring problem.

 

I have to sign off for the night but I wanted to post this UPDATE:
I removed both valve covers and the UVCH connectors were both plugged in & tight. I unplugged them and all of the pins look good. All of the injectors are the same except the front drivers side, it is bright yellow and has REMAN on it. I had my wife start the truck and it was running a bit rough but not bad. I have oil flow from all 8 injectors but it looked like the drivers side has more flow than the passenger side but that might just be because the oil dump ports are easier to see on the drivers side. I unplugged each injector and noticed a significant change in the engine with each injector. My wife said the tach needle dropped about ½ a notch each time I unplugged an injector. All of the rockers seemed to have the same amount of travel and seemed to move freely.
Any ideas or suggestions before I put the valve covers back on?

 

I am having the same problem whin I started my truck yesterday it started hunting up down idle . I cut it off and restarted it and it was ok then It got worse at lunch and even worser took all most 10 mins starting and stoping and restarting it be for it ran good. Got home 1 hr away cheeked fuel filter dirty change it out and it started ok. cleaned shop restarted truck and it started hunting agen . So I am cleaning the EBPS and tube witch I read on ford powerstroke site and found tube was clogged and wore through . So now I need a tube 70.08 and ebps is 325.00 wt- and I dont even know if this will fix it. Been on here just about all day trying to find whats wrong. For the last two weeks I have been smelling diesel fuel and could not find a leak . I was a diesel mechanic for the Navy. But I just dont get all the electronics and sensors. So I am watching this thread

 

twister when I would smell diesel in my cab with air on I found out that the little yellow fuel release on the side of filter housing had wore out o ring that leaked fluid into vally of intake. u wont see it leaking because it blows back behind motor while driving! look down in there for fuel and see if its there! if so u have to rplace that lever about 60 bucks at dealr

 

Dam thats rignt I have change it out before thanks. Do u know any more on what we have been talki g about was all most stranded yesterday

 

my truck did this we changed icp ipr uvch found it it was the idm good luck