I just drove about an hour at highway speeds. 70 mph +-. No issues. I get off the highway and stop at a light on the feeder. The truck feels sluggish but gets up to about 40 mph. I was at about 1/4 tank so I get about 25 gal of diesel. Now driving home it won't go over 1000 rpm and 3 mph tops. What the heck happened?? I disconnected the battery after crawling 5 blocks to the house for about 20 mins. Reconnect and it still won't go over 1000 rpm and 3 mph. I need some help guys. I'm sure this isn't the first time this ever happened to a 6.0L. Its in a '04 Excursion. Factory, no mods and no deletes. Thanks

 

Do you have any way to monitor or check for codes? Fuel pressure?

 

No. I'm not showing any check engine lights. I don't have a reader. I checked with two mechanic buddys. One said it's probably the hpop but a scanner would tell for sure. Also could be water separator/fuel filters. I have no white smoke in the exhaust though. thanks

 

I wouldn’t drive it any more until you figure it out or it may get exoensive fast. Low fuel pressure could take out all your injectors. Don’t throw parts at it, get a way to monitor readings and check codes and post them up.

 

Do you have a boost gauge? If so, is your needle moving at all?

 

Now it turns over and tries to start but it won't.

 

Check for codes and check fuel pressure

 

I had a problem that sounds somewhat similar with my 03. It just died 3 times over about 3 weeks, ended up on a flatbed 1 of those times. At it's worst point it would only idle. If I gave it any fuel it would die. I can't remember if it ever got to the point of no start. After having a diagnostic run on it it turned out to be some bad injectors.

 

Forscan or Torque Pro with the appropriate OBD adapter for your equipment
The thread adapter and a pressure gauge to read fuel pressure would be helpful
Need to read:
voltages - PCM, FICM input(x2), FICM output
pressures - ICP, IPR%
CODES
This is a base starting point for all troubleshooting on these trucks

 

Check the egr. Lots if times before I unplugged mine it would roll lots of white smoke and be gutless. Easy free check

 

Not sure what the required oil pressure is on this 6.0. Anyone know? Pressure checked the oil system. Seems to be a leak. Pulling valve covers to locate. Is there anything to be sure of while its torn down this far? thanks

 

500 psi to start.

Inspect the orings on the standpipes and dummys. If they dont have the white teflon upgrade them.
If you pull injectors I highly recommend replacing the copper washer and the orings - there are kits you can buy (only if you put the old injector back)
Make sure you inspect all the injector harness wiring and make sure everything is plugged in properly

Injectors are 24 ft lbs for the t40 and 26 ft lbs for the t45
Oil rail is 120 INCH POUNDS (10 ft lbs)
Dummy plugs/Standpipes 60 ft lbs

 

You can thank bismic for this. I found it in the 6.0 Tech Folder at the top of this section of the forum. If you are going to work on that 6.0 you need to research and get familiar with it.

Tech Folder- (read up)

https://www.ford-trucks.com/forums/3...ch-folder.html

The minimum engine oil pressure (low pressure oil) specifications are 82.7 kPa (12 psi) at 700 rpm, 165.5 kPa (24 psi) at 1,200 rpm and 310.3 kPa (45 psi) at 1,800 rpm with the engine at operating temperature. Low or no pressure could be caused by the oil pressure regulator, gerotor oil pump or an internal lube oil pressure leak. The engine will not start until the PCM reads 500 psi from the ICP (High Pressure Oil). The HPO pressure will range from 625 psi at idle and 4045 max psi with full engine load. a fast idle with no load will be about 1450 psi. This can be checked via the ICP sensor port.

The oil pressure sensor is just a switch that sends a signal to the instrument panel gauge. It closes a circuit to ground when the oil pressure reaches 5-7 psig. When the pressure is above 7 psig, the gauge will read normal. When it drops below 6 psig, it will read zero. The info from the switch does not feed back to the PCM in any way. The oil pressure regulator opens at pressure of 75 psig to send flow back to the pump suction.

 

Got it going again. Running fine. Replaced Hpop, EGR cooler, fuel filter. Installed oil pipe teflon ring update kit. The fuel filter showed no issues with water but it was due. Hoping to go another 180K miles. thanks guys.

 

Very good! What do you think it was based on the parts you replaced?