intermittent P0300 on my 2005 CRD

[seafish]

Was riding Giddyup home from work the other day and 3 miles from home she started to limp and stutter unless I kept RPMs very high and even then she was running rough. At idle she would almost die. But no CEL lit on the board.

I immediately though no power might be a boost leak, so I checked all hoses from intercooler to EGR valve and found with no leaks EXCEPT for a tiny one at or near the EGR valve.

Then I checked codes and got a pending P0300 for multiple misfires.
But I have NO idea how a P0300 for multiple misfires pertains to a diesel.

Please explain if you can…TIA

 

[seafish]

This morning I cleared the code and on a 5 mile test drive and she ran fine again.

Ideas??

 

[KJowner]

Air in the fuel system I'd guess.

 

[seafish]

Air in the fuel system I'd guess.

Source of air would be an unknown leak somewhere?? Or?

 

[seafish]

Time for the in Dodge Ram in tank pump upgrade?

 

[seafish]

@KJowner

This is what my Brave AI says…sounds about like what you said just with more details

"P0300 Liberty CRD Fuel Issue"​

The P0300 code in a 2005 Jeep Liberty CRD can be caused by air in the fuel system, which can lead to misfires and other engine performance issues.234 Symptoms of air in the fuel include rough idling, stalling, and a loss of power, especially when going uphill or under load.234
To address the issue of air in the fuel, you can check for leaks in the fuel system, particularly around the fuel filter head, as it is a common area for leaks in the Liberty CRD.234 Additionally, inspect the connections between the fuel lines and ensure they are properly sealed to prevent air from entering.234
If air is found in the fuel system, you can try bleeding the system using the hand pump and bleed screw on the fuel head to remove any air.234 If the problem persists, it might be necessary to replace the fuel filter head with a metal one, as the original plastic head can develop leaks.234"

 

[KJowner]

You could try poly tubing temporary plumbed in as fuel line, it's translucent so you can see bubbles, handy for locating leaks, you don't want to drop the fuel tank if you don't have to!

Like your link says the common leak seems to be the fuel filter, I've got the earlier Racor on mine so a bit less hassle, I see the Chinese have now copied them and are selling them on Amazon etc for less than 1/4 the price of a real one, might be worth a try, just remember you need one with the hand pump!