Hello, Just joined DB in the hopes that someone here might be able to offer additional insight into the problem with my 05 2.8 liberty CRD with 80k miles. I will try to keep the description brief, but with all the details.
This problem started as intermittent over several months. I thought it was fuel filters as I would replace them and it would be fine for a bit, until one day on a 300 mile trip I stopped near the end for fuel. after I left the station It went into what I now believe to have been limp mode and I stopped and replaced the fuel filter thinking I got bad fuel, but no change. Would die under any load, but would start and run fine right away, but with no power, 50 mph tops and 30+- on hills. Fine the next day. Shortly after that the problem was continuous after 5 min warm up. Runs fine with full power during 1st 5 min while cold.
I have ran the gamut. Original codes were intermitant P0093, and continuous 401 and 299 for Low turbo boost and EGR. I cleaned the boost/air temp sensor as well as MAF and Map and replaced original fuel filter head with aftermarket. Added 10 psi electric lift pump and installed 2' of clear fuel line in a loop after filer head to insure air free system. Pulled CAC hoses for inspection and cleaning. I ended up replacing the EGR as those codes were continuous. After EGR was replaced, no more code 401 or 299. However that was when the P0093 started being set continuously.
I have done all the checks for Fuel quantity solenoid (MPROP) the Fuel pressure solenoid (Pressure regulator), Air flow valve, wiring, and Turbo control. All research indicates the Fuel quantity solenoid fails more often and so that was the first valve I replace. No change, then the Fuel pressure solenoid was replaced and still no change. No additional codes that were not due to things I did and they went away never to return.
P0093, depending on who you chat with and what source one is looking at, it can indicate either high pressure or low pressure in the fuel rail. So going back to the original symptoms of being heat related (runs fine cold) does not fail until after a 5 min warm up, tells me the system is capable of building and running full system fuel pressure, something is amiss to send it into limp mode. Runs fine, just no power thus limp mode, dies completely under load, but will immediately restart fine, can anyone suggest what I should check now. My next step is to double check wiring and connectors and retest the pressure sensor hot and cold. How would I verify if the ECM is actually faulty?
I purchase the 05 manuals on disk a long time ago, but I recently downloaded the 06 off of Lost Jeeps so I have all that information. I don't know if DB has a link for a similar page.
Thanks to who ever reads this for your time.