First I'd heard you had access to live data, which apparently shows that the FPS is working, otherwise you presumably wouldn't have a reading in your live data? Sorry I missed that, but if there are any other pieces of evidence that you hadn't included before, it would probably help to mention those now.

A very risky move might be to briefly disconnect the cam sensor (so engine does not fire) and then disconnect the rail solenoid, too. Crank briefly to see if it makes a difference in how the rail pressure rises as you crank. This was suggested to me by a long-time member here, but I didn't need to do it: in my case I quickly narrowed my issue down to the FPS. But it would be nice to be really confident that your pressure readings are accurate, and not the result of a soft failure of the FPS. If it is the solenoid, it looks like that is pretty tricky to replace. Hope you get lucky!

_________________
George Reiswig
2005 Jeep Liberty CRD
Suncoast, SEGR, lift, InMotion tune, homebrew B100
At 138k, new head & gasket, timing belt, rockers and swearing vocabulary

Ok, i am about ready to say f*** this thing and send it to the dealer.

AFAIK it was running just fine on thursday until it just stopped. Would an injector just all of a sudden go bad? i was thinking the fuel pressure regulator simply because it happened all of a sudden. next step i guess is to remove the return rail on top of injectors and insert clear vinyl tubing to make sure injectors aren't bypassing to much fuel.

Thanks.

_________________
2006 Liberty CRD, 2.5" straight pipe, ccv mod, ts mp8 programmer(couldnt afford GDE HAHA). Otherwise stock.

First, SEARCH the thread where GDE solved similar failure with instructions for observing injector-return volume, for additional information

It seems overwhelming because you're seeing several possibilities all posted together - every journey begins with a single step - address the suggestions one at a time - you're endeavoring to eliminate any\allcomponents that are not involved, resulting in most likely suspect

Seems as tho you have capability to view live operational data - compare measured\actual rail pressure to ECM demand\command pressure when cranking

- the two should match: ECM demands 1800psi, FPS sensor should indicate 1800psi

- observe ECM demand when rail pressure drops off and settles to ~1200-1300psi

- if demand drops and measured follows, ECM is commanding no-start

- if demand is steady when measured drops, then a solenoid or sensor error, or failed injector

- power-off, recrank while observing fuel-return port to note return volume during pressure drop - if demand is steady when pressure drops indicates RPS leak

- separate injector fuel-return lines to note any increased flow when pressure drops

Don't forget to power-off between each test to reset ECM so it will allow cranking - ECM controls starter solenoid

It would be most helpful to have a volunteer managing the start switch while you are under the hood performing the several required machinations, as some of the observable events can occur rather quickly, and return fuel should be spilled\collected in a suitable container - raw liquid Diesel fuel is flammable

_________________
'05 CRD Limited
Pricol EGT, Boost
GDE Hot '11; EDGE Trail switched
SEGR; Provent; Magnaflow;
Suncoast T\C, Transgo Tow'n'Go switch;
Cummins LP module, Fleetguard filter, Filterminder
2.5" Daystar f, OME r; Ranchos; K80767's, Al's lifted uppers
Rubicons, 2.55 Goodyears
Four in a row really makes it go

Live data only displays absolute fuel pressure. I only have a cheap actron scanner lol

_________________
2006 Liberty CRD, 2.5" straight pipe, ccv mod, ts mp8 programmer(couldnt afford GDE HAHA). Otherwise stock.

Injector leak test:

viewtopic.php?p=846239#p846239

AUTOENGINUITY offered a pc-based full-test scantool that would duplicate all DRBIII\STARSCAN tests, plus many more - search them on eBay and 'net -

I had used AE extensively on my GM 6.5LTD, the 24v CUMMINS, and this KJ, but it resides on a now-defunct DELL laptop - I may try to revive that this winter when I'm weathered-in, as it's way more useful than the DRBIII

Also, IIRC, SCANGAUGE can be manually programmed to look at all parameters, and desired codes can be stored in a list for re-viewing - it is functional as scantool in PARK mode, but severely interferes with Antilock Braking System when driving, and can cause major hiccups, recoverable only after stopping and key-off - failures will occur again while driving

All parameter codes can be found in published OBDII code listings as provided by AE and SCANGAUGE, also available on 'net - these codes, not to be confused with failure DTC's, are the oem-sanctioned parameter codes which scantools must use for observing operational data-points in the various ECM\ECU\PCM\PCU engine-managment computers, and which must conform to the OBDII sanctioning body specifications -

'Nuther words, the code for rail pressure will be same for DCJ, FMC, GMC, MITSUBISHI, TYOTIE, SUBARU, ISUZU, HONDA, HARLEY DAVIDSON, etc, etc -

OBDII parameters also required EPA sanction to ensure uniform vehicle inspection monitoring\testing

Addendum: SCANGAUGE-II does have option to read OBDII parameter codes in XGAUGE, or Extended Gauge, mode - instructions for use are in installation\operation manual, also on their website

Can be programmed such that each screen will read up to four (4) OBDII parameters

Again, SCANGAUGE II is fully functional when KJ is standing still - driving will cause known problems

_________________
'05 CRD Limited
Pricol EGT, Boost
GDE Hot '11; EDGE Trail switched
SEGR; Provent; Magnaflow;
Suncoast T\C, Transgo Tow'n'Go switch;
Cummins LP module, Fleetguard filter, Filterminder
2.5" Daystar f, OME r; Ranchos; K80767's, Al's lifted uppers
Rubicons, 2.55 Goodyears
Four in a row really makes it go

Have any thoughts or experience on ScanTool 425801 OBDLink SX OBD-II Scan Tool,
I have it on a laptop, have not played around with it much though.
Do you know if it will read most of the Jeep CRD parameters?

_________________
Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount
98 Dodge Cummins 24 Valve

No experience with that setup - but, if the package included the OBDII code listings, the KJ CRD codes conform to OBDII standard and are identical - look in the KJ DTC listing for specific mnemonics, the accepted descriptive phrases for each parameter, which links the OBDII code to the appropriate DTC

OBDII specs that the fuel rail must be referred to as 'fuel rail', and not the 'squirt log' - injectors have been known as 'squirts', when being discussed under a shade tree

If no listings were supplied, search\google OBDII and you'll get a veritable plethora of sites posting the standardized listings

When you have the listings, plug the connector into the KJ OBDII port under the dash between the steering column and console and do a scan, IGN on, not running - see if the available codes in the scantool list the desired OBDII-listed codes, go from there

If not listed but it's a quality comprehensive setup, you should be able to program the scanner to read any standard OBDII code - some allow you to fill out a list of desired codes which may be stored for ease of access on each vehicle to be scanned

Addendum: SCANGAUGE-II does have option to read OBDII parameter codes in XGAUGE, or Extended Gauge, mode - instructions for use are in installation\operation manual, also on their website

Can be programmed such that each screen will read up to four (4) OBDII parameters

Again, SCANGAUGE II is fully functional when KJ is standing still - driving will cause known problems

_________________
'05 CRD Limited
Pricol EGT, Boost
GDE Hot '11; EDGE Trail switched
SEGR; Provent; Magnaflow;
Suncoast T\C, Transgo Tow'n'Go switch;
Cummins LP module, Fleetguard filter, Filterminder
2.5" Daystar f, OME r; Ranchos; K80767's, Al's lifted uppers
Rubicons, 2.55 Goodyears
Four in a row really makes it go

There should be no fuel coming out of the blue line in front of PCV on back side of rail during the cranking. Since it is, the PCV is sticking open and failed. Did you happen to pull the connector to the PCV and #4 injector recently? Swapping these will cause a no start. The PCV is about $500, so rule everything else out before shelling out cash for a new one.

_________________
Providers of wholly developed aftermarket solutions for the KJ CRD.
(248) 977 - 9531

I thought so, just couldnt get a straight difinitive answer. No connectors have been diconnected/reconnected except in the fuel head. BTW gde, you are right around the corner from me city wise. I am in Holly MI. Are there any other tests you would recommend and or explain how to do? I already know the injector spill test, however i do not have the graduated vials. what size clear tubing should i get for that test, and anything i should know before(check valves, priming injectors, etc.)? Thank you!

_________________
2006 Liberty CRD, 2.5" straight pipe, ccv mod, ts mp8 programmer(couldnt afford GDE HAHA). Otherwise stock.

The Fuel Pressure Reglator currently listed on eBay is actually the Fuel Quantity Solenoid which mounts to the CP3 IP - the Rail Pressure Solenoid FPR is screw-in type in rear of rail - RPS FPR pressure control valve* 5159964aa

GDE is correct, with one caveat - rail pressure indicates 1800psi, then drops to ~1300psi - the FPR solenoid spring tension will bypass to ~1300 psi without ECM control - the readings appear correct for ECM controlling the solenoid

Possibility ECM is initially controlling FPR to 1800psi when solenoid coil opens, releasing plunger with resulting normal bypass to 1300psi

Also possibility: ECM is controlling FPR to 1800psi when a 'nuther critical fault causes ECM to release FPR, resulting in drop to normal FPR bypass to 1300psi for a commanded no-start conditon

Without dynamic scantool, ur guess is good as mine - a $400 no-fix guess is way worse than mine.........................

* PCV aint even a good abbrev for this solenoid, in OBDII or anywhere else...........

_________________
'05 CRD Limited
Pricol EGT, Boost
GDE Hot '11; EDGE Trail switched
SEGR; Provent; Magnaflow;
Suncoast T\C, Transgo Tow'n'Go switch;
Cummins LP module, Fleetguard filter, Filterminder
2.5" Daystar f, OME r; Ranchos; K80767's, Al's lifted uppers
Rubicons, 2.55 Goodyears
Four in a row really makes it go

PCV is the Bosch terminology (Pressure Control Valve), since they made the part we left their name alone. GM might call it a fuel cascade valve. A similar part is used on virtually every Bosch common rail fuel system in the world.

The rail must pressurize to 170bar roughly before the injector will fire. During the warm-up the PCV regulates pressure in all conditions. At idle the rail pressure is about 300bar. 1800 psi is too low for anything and the valve should be closed to increase rail pressure to the desired range.

It could be bad wiring leading to improper current flow and the valve is not closing properly. It is hard to check for a load drop in wiring if you have continuity in the circuits.

_________________
Providers of wholly developed aftermarket solutions for the KJ CRD.
(248) 977 - 9531

Understood - PCV it is in the parts manual - also Positive Crankcase Ventilation in OBDII - Bosch also programmed ECU's for gasoline-fueled EFI engines with PCV's - too bad they did not differentiate the two concepts by rail pressure valve, or rail pressure solenoid, even as opposed to fuel pressure sensor, which some fuel supply\delivery systems have in the lift-pump circuit

Good info on starting pressures, more official than I had seen - got more info somewhere around here -

I'll be back...................

OK, it's my understanding that the injectors will open at any pressure if ECM commands - ECM widens pulses to send hi-current to coil,
required to equalize rail pressure across armature - armature movement then requires less magnetism as pressure equalizes, ECM then reduces
current, ball pops off seat, fuel flows past needle into nozzle = injection

Only reason injectors don't function is if ECM is looking for a certain minimum rail pressure, which you indicate is 2550psi - if pressure is
low, ECM will not fire injectors, will close FQS, will stop controlling rail pressure control valve, which will then vent till rail pressure
drops to ~1300psi

That appears to be what is occuring in this scenario
- key on, begin cranking engine
- ECM leaves FQS open ensuring CP3 pumps maximum volume into the rail
- ECM forces rail pressure control valve closed for maximum pressure rise during crank
- rail pressure quickly increases to 1800psi then drops just as quickly
- - does ECM command no run condition?
- - is rail pressure control valve solenoid defective?
- - is ECM driver defective?
- - is injector ball\seat blocked by grain of sand, bypassing almost-nearly-injected fuel into return-fuel line?
- - is injector needle jammed by grain of sand, same result?
- control valve then appears to bleed off at designed 1300psi pressure - rail pressure never recovers
- key off
- key on, begin crank, same result

If it's not injector bypass, some significant outlay will be required to initiate troubleshooting


Addendum: SCANGAUGE-II does have option to read OBDII parameter codes in XGAUGE, or Extended Gauge, mode - instructions for use are in installation\operation manual, also on their website

Can be programmed such that each screen will read up to four (4) OBDII parameters

Again, SCANGAUGE II is fully functional when KJ is standing still - driving will cause known problems

_________________
'05 CRD Limited
Pricol EGT, Boost
GDE Hot '11; EDGE Trail switched
SEGR; Provent; Magnaflow;
Suncoast T\C, Transgo Tow'n'Go switch;
Cummins LP module, Fleetguard filter, Filterminder
2.5" Daystar f, OME r; Ranchos; K80767's, Al's lifted uppers
Rubicons, 2.55 Goodyears
Four in a row really makes it go

I realize this is an old thread but what was the final verdict as to your problem?

The problem was a failed Fuel Pressure Bleed-off valve.
This is not the correct component name, but it correctly describes it's function, and the manufacturer and the Factory Service Manual can't even agree on the name, but this link is the actual component. PN RRD5159964AA
https://oregonfuelinjection.com/shop/jeep-diesel/2005-2006-2-8-l-jeep-liberty-diesel/fuel-cntrl-vlve-mnt-on-rail-librt/
and it's probably the best price you will find for that component alone.

This is the installation proceedure
http://www.colorado4wheel.com/manuals/Jeep/KJ/2005JeepKJServiceManual.pdf
starting page 1613, section 14 - 86 - FUEL INJECTION - 2.8L DIESEL KJ

However, if you order the complete rail
https://oregonfuelinjection.com/shop/jeep-diesel/2005-2006-2-8-l-jeep-liberty-diesel/fuel-rail-exchange-jeep-liberty/
you get a completely rebuilt assembly WITH warranty, and WITH BOTH (RRD5159964AA)
and (5159963AA, 68020556AA) https://oregonfuelinjection.com/shop/jeep-diesel/2005-2006-2-8-l-jeep-liberty-diesel/rail-pressure-sensor-jeepgm/installed.


Yes, you read that correctly, you get a completely rebuilt, tested, certified, and warrantied rail WITH a new $390 Valve AND a new $190 pressure sensor already factory installed for $356, + a $300 core charge, which is universal no matter who you buy from. There is also a 10-14 day lead time (average range) which for that kind of savings I have no problem with.

So If you can verify that the ECM is properly identifying all of the possible errors involved with the (Fuel quantity valve, MPROP, etc etc); the Fuel Pressure Sensor, and the valve at the rear of the rail, thus ruling the ECM and wiring out, then you can replace all of the other 3 components in one bang for less than $430.

Before I made this jump, I made sure that it wasn't a compression or air supply issue, and did several code clearing cycles to make sure there were no hidden issues. If it works, I will let everyone know when it gets here.

_________________
'06 Lbrty Sprt CRD 150K

Sasquatch
DSS Turbo
CAT-elimntr
Weeks Stg1&2 EGRfix
PV-200
BLING
vent gauges

IDParts
head
cams
rockers
Timing set
ARP studs
eTn1 GX2123 5v GPs

YETI Custom Tune
Flowmaster 8325508
Carter P76611M
GM 12611872
Hayden 2986
GM 15976889
PATC Custom Billet
2010 Ram Hemi Trans
Sonnax 44957
Transgo kit
Cooper 51770

The check engine light in our 2006 CRD recently came on and at the same time, the Jeep experienced reduced power. I think it went to limp mode. I pulled the codes and found P0403 (EGR has been disabled for >100K mile), P0093 and P0203 (#3 injector). My wife said the last time she refueled, the tank was very slow to fill. I replaced the CRD fuel filter thinking the diesel she purchased may have some trash in it. While I was under the hood, I checked the wires to #3 injector. I found the insulation was worn through one conductor where it exists the plastic cable tray on top of the engine. I saw no indication of it shorting to ground or shorting to any other wires. I re-taped and repositioned the injector wires. I cleared the codes and went for a drive. After about a 1/2 mile, the check engine light returned. I pulled the codes and found P0403 and P0093.

Did the rebuilt fuel rail solve the problem?

Update: I cleared the codes and the Jeep has been idling for about 15 minutes and the check engine light hasn't turned on......yet.

_________________
2006 CRD Sport
GDE FT ECO tune, GDE TCM ECO tune, ARP studs, HDS-001 203F T-Stat, 3.7L nylon fan & Hayden 2905 clutch, Carter P76148M in-tank pump, Racor 245R122 filter head & 2 micron R25S fuel filter, Provent 200, Samcos, Fumoto F-102, Litens 920834A de-coupler, PML rear diff cover, OEM trans pan with welded in bung, JBA UCAs, full skids.

Start by checking everything on the low pressure side.
You already replaced the fuel filter.
Make sure your lift pump works.
Make sure you have no leaks and no air in the lines.

_________________
U.S. Army Retired

Lift pump works. I used it to fill the fuel filter.

Update: I found a LARGE puddle of diesel under the Jeep after it had been idling for about 25 minutes. The fuel return line from #1 injector was broken off at the injector. I must have broken it when I was working on #3 injector wire. Not sure how I did this......I guess it could have been brittle and it snapped off. After 25 minutes of idling, still no check engine light.

I'm inclined to believe the pressure in the fuel rail is low, because the check engine light does come on until I accelerate. I'm puzzled by the #3 injector trouble code. Can low fuel rail pressure cause one of these?

P0203-CYLINDER 3-INJECTOR CIRCUIT CURRENT INCREASE.
P0203-CYLINDER 3-INJECTOR CIRCUIT CURRENT DECREASE.
P0203-CYLINDER 3-INJECTOR CIRCUIT LOAD DROP
P0203-CYLINDER 3-INJECTOR CIRCUIT OVERCURRENT HIGH SIDE .
P0203-CYLINDER 3-INJECTOR CIRCUIT OVERCURRENT LOW SIDE.
P0203-FUEL INJECTOR 3 CIRCUIT

_________________
2006 CRD Sport
GDE FT ECO tune, GDE TCM ECO tune, ARP studs, HDS-001 203F T-Stat, 3.7L nylon fan & Hayden 2905 clutch, Carter P76148M in-tank pump, Racor 245R122 filter head & 2 micron R25S fuel filter, Provent 200, Samcos, Fumoto F-102, Litens 920834A de-coupler, PML rear diff cover, OEM trans pan with welded in bung, JBA UCAs, full skids.

Oregon Fuel Injection has replacements, they're used on several different engines with Bosch injectors: https://oregonfuelinjection.com/shop/sprinter-van/2004-2006-2-7-l-sprinter-van/return-conn-90-degr-cr-inj-lly/

No, that would most likely be a wiring issue, or possibly a problem with the injector itself.

If injector 3 was somehow stuck open, that might cause a low pressure problem.

If you do a injector return flow test and #3 is not the same as the others, then the injector is probably the problem.

Also, double check the wiring to the injector and make sure the connection is tight.

_________________
U.S. Army Retired

_________________
'06 Lbrty Sprt CRD 150K

Sasquatch
DSS Turbo
CAT-elimntr
Weeks Stg1&2 EGRfix
PV-200
BLING
vent gauges

IDParts
head
cams
rockers
Timing set
ARP studs
eTn1 GX2123 5v GPs

YETI Custom Tune
Flowmaster 8325508
Carter P76611M
GM 12611872
Hayden 2986
GM 15976889
PATC Custom Billet
2010 Ram Hemi Trans
Sonnax 44957
Transgo kit
Cooper 51770