Anyone who reads this and can suggest what I am missing I would really appreciate it,,,,Havn't been here in 'bout 120k miles,but I need some imput, short story is this: sticking injectors, typ smoke at idle etc, did start but fogged at idle, at the same time had a p0192, new FPS, 5V feed good, code cleared, new 50 injectors, fog at idle cleared, this is where it gets weird, Hooked up a scan tool and saw all this new info , like rail pressure!, fluctuating all over, good at idle, falls off at high idle, ok...but down the road at 60, 70 WOT nothing more tha 9,500 (62-66,000Kpa),Checked LV, puking fuel, capped no better, ordered new cprv, (T&C) ,,FCA failed the shake test(kinda,, lol)new FCA, same,,, umm, noticed IAT was oddly high, cleaned MAP, better, not making what I believe to be normal pressure,,12-14 at 65-75mph with a hill, 22-24 at WOT, Next re-torqued connector tubes, from 37 to 44 ft lbs, less fluctuation but still no more Rail pressure than before, urgh!!!!! ok I make my living with this truck..new cp3 $$$,,,Back to work Priceless!!!! in goes new cp3 +20%, truck runs good, no coal, quadz, off as in disconnected, max rail pressure still 9,500

....Please don,t say ECM,,,,


Forgot to say, fass 95 14lbs....

 

Is there a way to test a fuel pressure sensor?

 

12-14 k at 65-70 mph (on a neutral throttle), and 22-24 k WOT (when not in lock up) is what I generally see, though I have an 03 not an 05. WOT when in lock up (whilst you are cruising at 65-70mph plus), should still give you more than 9.5k, I see around 15-20 for this.
Did you replace your injector tubes with the injectors?, if one of them is slightly damaged fuel can leak by the connection causing your pressure to fluctuate.
Call Todd At TC Diesel, he sold me a good used rail pressure sensor for much less than a new one, you may get lucky like me.
Good luck.

 

Kingey,
Thanks for the response,,

I Did not replace them, but i did polish up the ends and inspected them closely,,,,

,,,However I may have discovered the problem, and I'm embarassed to admit it, but in opting for finer filtration I put a parker/racor 2 micron filter on my platinum fass, and just noticed it not suited to that pump, It is designed to be on the suction side not pressure side of a pump!!! Not sure what the implications of that is, but it's obviously flowing in the wrong direction, Correct filter ordered! Hope this fixes it!

 

If your injectors are bad, they're probably leaking internally past the seat. If you didn't take them apart, you'd never notice the signs, and even then it's hard to see without a very high power microscope. Leaking injectors will most certainly cause low rail pressure as they never truly close and are always flowing fuel.

 

Adaminak,

My injectors r new, I've decided it's electrical in nature, somethings, obviously wrong some where, and my battery votage is droping a little more each day,,,they r six yrs old,,and I understand new electronics are quite sensitive to voltage,it's really the only thing that has changed,,,

Also i can't see what the ecm is commanding at different loads,,so at this point i'll try new batteries and try to find a more through diagnostic tool,,
,,meanwhile I'll carefully start checking wires and connections...

 

Interestingly when I disconnected the FCA the engine knocked as it should with max preesure, but it didn't show on the scanner..?

 

that proves the rail pressure sensor is bad

 

That's what I was thinking also, However it is new, I tried the old one which was throwing 0192, and the readings are similar,,,umm, both bad?

I need to find a known good one to try...

 

Sorry...I see it now in your first post...my bad

I agree with Carl...if removing the FCA doesn't throw a code, there's something wrong either with the rail pressure sensor or the ECM circuit that monitors the rail pressure.

Quick thought: Have you pulled the connections at the ECM and cleaned them?

 

I only started it long enough to hear it, and shut 'er down, I don't think I gave it enough time to throw a code! lol
today disconneted the batts, and checked some undercarrage wiring, wanted to ""see for myself" looked pretty tight, noticed one connector soaked with oil on the side of tranny, cleaned and greased it.
Next I checked the wires to the RPS for ground 2open 1ground, as expected, hooked the batteries back up, checked same and had 2@5.02v, 1@0.0, dielectric grease start up (60*Ambient) and threw a p0193, I thinking fluke, cleared it and didn't come back,,but I didn't drive it just re-started it a couple times. I put a hold on the new Batt's as the Voltage is back up, not needed the grid these last few days, 12.7v at the bat, 14.2 at idle,,,,


Oh, and no I have not disconnected the connections to the ECU, and cleaned them, I been a little leary of upsetting them,,

,,yet

 

..as I remember I saw like 45,000kpa with the fca unhooked, for .25sec before I freaked at the sound the motor was making! lol

 

Found this,,,,

FUEL PRESSURE SENSOR
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (F855) RETURN CIRCUIT
(K181) SIGNAL CIRCUIT SHORTED TO (F855) RETURN CIRCUIT
(K181) SIGNAL CIRCUIT OPEN
(F855) 5-VOLT SUPPLY CIRCUIT OPEN
(K181) SIGNAL CIRCUIT SHORTED TO GROUND
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
ECM
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1. OTHER DTC’S
Ignition on, engine not running.
With the scan tool, read DTCs.
Do you have multiple DTC’s?
Yes >> Repair other DTC’s first.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No >> Go To 2
2. (F855) 5-VOLT SUPPLY AND (K915) RETURN CIRCUIT
Turn the ignition off.
Disconnect the Fuel Pressure sensor harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Ignition on, engine not running.
Measure the voltage between the (F855) 5-volt supply and (K915)
return circuits of the Fuel pressure sensor harness connector.
Is the voltage between 4.5 and 5.5 volts?
Yes >> Go To 3
No >> Go To 4
9 - 1220 ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL DR
3. FUEL PRESSURE SENSOR
Reconnect the disconnected Fuel Pressure Sensor harness connector.
While monitoring scan tool, disconnect the Fuel Pressure sensor harness connector.
Does the DTC P0193 set?
Yes >> Replace the Fuel Pressure Sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC
CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No >> Go To 4
4. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K915) RETURN CIRCUIT
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Fuel Pressure sensor harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance between the (F855) 5-volt supply circuit and
(K915) return circuit in the sensor harness connector.
Is the resistance greater than 100 K Ohms?
Yes >> Go To 5
No >> Repair the shorted circuits.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/ENGINE CONTROL MODULE - DIAGNOSIS
AND TESTING)
5. (K181) SIGNAL CIRCUIT SHORTED TO (K915) RETURN CIRCUIT
Measure the resistance between the (K181) signal circuit and (K915)
return circuit in the sensor connector.
Is the resistance greater than 100 K Ohms?
Yes >> Go To 6
No >> Repair the shorted circuits.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/ENGINE CONTROL MODULE - DIAGNOSIS
AND TESTING)
DR ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL 9 - 1221
6. (K181) SIGNAL CIRCUIT OPEN
Measure the resistance between the signal (K181) circuit in the sensor
harness connector with the (K181) signal circuit in the ECM harness
connector.
Is the resistance less than 10 Ohms?
Yes >> Go To 7
No >> Repair the open (K181) signal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/ENGINE CONTROL MODULE - DIAGNOSIS
AND TESTING)
7. (F855) 5-VOLT SUPPLY CIRCUIT OPEN
Measure the resistance between the supply (F855) circuit in the sensor
harness connector with the (F855) 5-volt supply circuit in the ECM harness
connector.
Is the resistance less than 10 Ohms?
Yes >> Go To 8
No >> Repair the open (F855) 5-volt supply circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/ENGINE CONTROL MODULE - DIAGNOSIS
AND TESTING)
9 - 1222 ENGINE - ELECTRICAL DIAGNOSTICS - DIESEL DR
8. (K181) SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between the (K181) signal circuit in the sensor
harness connector and battery negative.
Is the resistance greater than 100 K Ohms?
Yes >> Go To 9
No >> Repair (K181) signal circuit shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/ENGINE CONTROL MODULE - DIAGNOSIS
AND TESTING)
9. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between the (F855) 5-volt supply circuit in the
sensor harness connector and battery negative.
Is the resistance greater than 100 K Ohms?
Yes >> Go To 10
No >> Repair (F855) 5-volt Supply circuit shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/ENGINE CONTROL MODULE - DIAGNOSIS
AND TESTING)
10. ECM
Reconnect the disconnected Fuel pressure sensor harness connector and ECM harness connectors.
While monitoring scan tool, disconnect the Fuel Pressure sensor connector.
__________________


Can someone help me identify the Pin numbers? or asign a wire color to them?

I guess my question is which wire is supply, and which is return? and how would I identify the other ends at the ECM?

 

Dodgebodybuilder.com has the wiring diagrams.

MikeyB

 

If you connect your multimeter to the connections for the pressure sensor and it reads +5v, the the red lead is hot and the black to ground, if the meter reads -5v then rd is to ground and black to hot.