Possile fuel system issue?

[Chas501]

My 2002 7.3 Powerstroke runs rough and stalls when cold. Obviously starving for fuel, but replacing the filter and pump did not improve performance. Can anyone tell me how to troubleshoot?

I have a host of error codes, (ICP voltage, Injector control, low boost pressure, wastegate fail, ICP not controllable, Misfire) but they are all over the board, and I suspect they are the direct result of trying to drive it with inadequate fuel pressure, because when I let it warm up for 10+ minutes before starting out, I don't get error codes.

[jcs]

You should check the uvc harness other than that i don't know where to point you and welcome to the org.

[Chas501]

I don't think it is that sort of issue because it really feels like not enough fuel in general, not a single cylinder, and typically runs fine once warm.

It also is getting about half the mileage it should (13 highway) and takes about five pounds of boost just to maintain highway speed (65). It feels like it's starving for fuel and I was hoping it was a fuel pump but afraid it could be the injector pump.

When I switch on the key the pump runs but then shuts off in what seems like a reasonable time, so I guess it probably isn't the pump.

I read something about the water seperator, and will drain it today, but only mildly optimistic.

I'm also reading about the ICP Sensor, EGR, IPR, and CPS. I don't know what all of these are or how they affect performanc, so if anyone can help me confirm or eliminate these components that would be great.

[Big_Stroker]

ICP Senser is Injection Control Pressure. This could be your issue if its not working right. Or it could be that you just have a bad HPOP or some back injectors that don't work right until they are warmed up.

What happens when you run a BUZZ test b4 the motor is warm?

[Chas501]

I didn't find the water seperator. I thought it would be on top of the engine with a yellow hande or on the frame rail. Anyone know where it is on a 2002 Excursion?

I still don't think it's an injector issue because the whole engine looses power as if there is no fuel. If I try to take off the engine stalls from lack of fuel. It doesn't run rough like it would from a cylinder miss. I did get a cylinder miss error code, but only once and this has been going on for months. The whole engine was stalling, not just one or two cylinders. I don't know how to run a buzz test, but don't think the injectors are the issue.

I'm still hoping for something simple like the water seperator being full. It acts exactly like a clogged fuel filter or a weak fuel pump, but it isn't either.

I also don't know what an HPOP is, so someone help me out please.

Thanks for the suggestions, and please keep them coming. I'm a decent mechanic, but not nearly as familiar with the controls added to the modern deisels as I am with older farm engines.

I still believe this to be something simple, and hoping someone will recognize it or say something that gets me on the right track.

[ronhauser]

your hpop is your high pressure oil pump. I had same problem. Checked oil pressure from head and I was 1000 psi low. Installed new hpop and regained full power. oil pressure on diesel engine also runs injectors.

[szyd]

The fuel water seperator is on the top of the motor where the fuel filter is. If you look on the back side of the filter housing you will see the yellow lever. Have you reaplaced the filter? It also sounds to me like it could be the ICP sensor. A cheap and easy way to diagnose is to try the 10K mod.10k resistor mod.

[szyd]

the HPOP is the high pressue oil pump that is responsible for presurizing the fuel in the injectors. The ICP controlls the pressure of the oil. Oil is a huge factor in these engines the wrong oil or old dirty oil can also cause these issues.

[Chas501]

Congratulations...we have found what appears to be a main root cause. I didn't realize until recently that the injectors are oil fired, and it appears that during the last oil change, I didn't quite top up the oil. This is partly because my dipstick is broken, but between that and a little leakage, the oil level dropped enough to lower the HPOP pressure. I would never have thought my oil could be the cause because I thought the injectors were electronically fired like most gas engines.

The cold engine fuel starving issue stopped altogether, and the highway milage is up about 7 MPG to 19. The only issue that remains is that the engine surges at lower RPM, but based on something I read, that could be a side affect from the superchip.

Thank again for the input