Head gasket change, no start, P0192

greiswig · **Posted:** Sat Nov 01, 2014 8:54 pm

So I finally have my rig back together to a point where I can try firing it up. I had to change the head and head gasket, as well as rockers. So everything from the block up was off and unplugged. I bled the filter head, and have a lift pump that should be trying to push any bubbles through the pump, but the rail probably had some good air pockets in it. Hard to disconnect that without losing fuel from it.

It still has all the front off: grill, headlight assembly, etc.

Before I even cranked it, I decided to read the codes with the ignition switch on, just to see if perhaps I had left something unplugged. Two codes came up: P0073 (ambient temp, which I gather may have something to do with a sensor on the grill? If so, not too worried about that and wouldn't expect it to prevent firing) and also P0192.

P0192 seems to be rail pressure low? Even before cranking?

Tried starting it anyway, but no dice. It cranks fine, but isn't even trying to fire. Any thoughts as to where I should start looking?

EDIT: one other thing. I didn't bother trying to "time" the injection pump. It didn't seem to be lining up with anything in particular when I pulled the old belt off, and it makes sense to me that this just supplies rail pressure continuously and so shouldn't need to be indexed. Was I wrong there?

greiswig · **Posted:** Sat Nov 01, 2014 10:12 pm

Can't locate in the copy of the manual I have: is there a proper procedure for bleeding the fuel rail and injector lines?

gmctd · **Posted:** Sat Nov 01, 2014 11:25 pm

I'm still not comfortable with timing the 3-cyl CP3 with 120deg pumping pulses to a 4-cyl engine with 90deg combustion events, but if you do a search back B4 2010, when I quit posting\reading, someone posted pertinent info regarding this concept -

Mike92104 · **Posted:** Sun Nov 02, 2014 12:00 am

Geordi would know more, but I believe the fuel pump only lines up with it's mark on every third revolution of the engine. It is supposed to be timed, but there is a lot of debate on whether or not it's necessary. Chances are you won't notice a difference.

On the non starting, could it be this:

viewtopic.php?f=5&t=80462

Mike

greiswig · **Posted:** Sun Nov 02, 2014 11:23 am

greiswig wrote:

Can't locate in the copy of the manual I have: is there a proper procedure for bleeding the fuel rail and injector lines?

Anybody? For example, does the engine have to be cranking (main pump rotating) or is pushing fuel through it via the lift pump and filter pump sufficient? Do you have to prime the pump first, then the rail? Things like that.

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

P0192 is an open circuit on the rail pressure sensor. Check the wiring and sensor first.

greiswig · **Posted:** Sun Nov 02, 2014 11:49 am

GreenDieselEngineering wrote:

P0192 is an open circuit on the rail pressure sensor. Check the wiring and sensor first.

Thanks much for weighing in. So that is registering a completely open circuit, not just low reading at the sensor?

First of all, which is the pressure sensor...the one at the very back of the rail? (EDIT: I finally found a section of the manual with some wiring info...sensor is the 3-way connector, pressure solenoid is a 2-way)

Secondly, what ohm reading (or is it not resistive?) should I be looking for across that sensor with the engine not running?

Third, if I poke with an ohmmeter on the connector leads for that sensor, any ideas what kind of resistance I should be seeing between each lead and ground? Or is there a different way to measure that part of the harness? (EDIT: I guess the first test should be looking for a good ground connection and 5 volts, but if both those are good...?)

Fourth...nobody here has ever needed to bleed the fuel rail?

gmctd · **Posted:** Sun Nov 02, 2014 12:32 pm

Bleeding the injector pipes was very important @ 1250-1800psi because compressed air could not 'pop' the mechanical injectors - not so much so at 6500psi (idle) ~ 22,000psi (driving) with modern electronic injectors

P0192 is an open circuit or lack of connection to the rail pressure sensor - ECM has no response from Fuel Pressure Sensor FPS, so cannot determine what quantity of fuel is necessary - FPS is the one screwed into the left rear side - FPR Fuel Pressure Regulator is screwed into rear end -

IIRC, there are two (2) connectors in that area that can be cross-swapped (maybe FPS and MAP?) - verify correct connection

Also, KJ Diesel Diagnostic Manual details the very tests you are asking about

WWDiesel · **Posted:** Sun Nov 02, 2014 1:19 pm

According to the wiring diagram:
Fuel pressure solenoid only two wires: colors BR/OR and BR both 16 ga.
Fuel pressure sensor has three wires: colors BR/YL and BR/YL and YL/BR all 20 ga.
MAP has three wires: colors: YL/PL and VT/BR and DB/DG all 20 ga.

hope this helps a little... :wink:

greiswig · **Posted:** Sun Nov 02, 2014 2:10 pm

Thanks again, all. Is there a place I can download this other manual for diesel diagnostics? I didn't see that one at the Colorado web site. But that's what I need to keep me from asking more dumb questions here.

gmctd · **Posted:** Sun Nov 02, 2014 2:15 pm

Dunno about downloadable sourcing, but I see them pop up on eBay every so often, up to ~$85 - pricing varies with demand

greiswig · **Posted:** Sun Nov 02, 2014 6:36 pm

gmctd wrote:

Bleeding the injector pipes was very important @ 1250-1800psi because compressed air could not 'pop' the mechanical injectors - not so much so at 6500psi (idle) ~ 22,000psi (driving) with modern electronic injectors.

Okay, but I have one friend who thought it helped. So is it generally known that this engine does not need it? I'm really asking, because I don't see anything about it in the manual.

gmctd wrote:

P0192 is an open circuit or lack of connection to the rail pressure sensor - ECM has no response from Fuel Pressure Sensor FPS, so cannot determine what quantity of fuel is necessary - FPS is the one screwed into the left rear side - FPR Fuel Pressure Regulator is screwed into rear end -

IIRC, there are two (2) connectors in that area that can be cross-swapped (maybe FPS and MAP?) - verify correct connection

Also, KJ Diesel Diagnostic Manual details the very tests you are asking about

I think the two connectors that could be swapped are the cam position sensor and injector #4. I don't seem to have done that.

Where are you getting your trouble code info? The same manual you refer to here?

Okay, now on to wiring:

gmctd wrote:

P0192 is an open circuit or lack of connection to the rail pressure sensor - ECM has no response from Fuel Pressure Sensor FPS, so cannot determine what quantity of fuel is necessary - FPS is the one screwed into the left rear side - FPR Fuel Pressure Regulator is screwed into rear end -

Then...

WWDiesel wrote:

According to the wiring diagram:
Fuel pressure solenoid only two wires: colors BR/OR and BR both 16 ga.
Fuel pressure sensor has three wires: colors BR/YL and BR/YL and YL/BR all 20 ga.
MAP has three wires: colors: YL/PL and VT/BR and DB/DG all 20 ga.

hope this helps a little... :wink:

I hope it helps a lot! ;-)

Thing is, my MAP sensor (the one mounted to the intake manifold under the fuel rail) is a four-conductor job. I can't find what the wiring codes are supposed to be on it, but mine seem to be gray/brown, brown/blue, blue/yellow, brown/orange or red.

That doesn't seem to map (pun, sorry) to yours at all. And what is PL?

On to my other connectors. I think I have them hooked up right, but somebody please tell me if I'm wrong:

At the rear of the fuel rail (pressure regulator if gmctd is right): blue/black, brown/red

Driver's side rail (FPS if gmctd isn't right): yellow/brown, blue/orange, blue/red

I have one connector dangling where the FCV used to be. No instructions came with the Weeks kit, so I assume that can be left open? Or can it?

And, again, I don't have my grill with headlights and such installed, so is it possible the FPS routes through that stuff somehow? I'd just rather not button everything up until I know it runs.

Thank you for the help!

gmctd · **Posted:** Sun Nov 02, 2014 7:02 pm

DTC LIST:

viewtopic.php?f=98&t=40073

Also pics of engine sensors'n'stuff in NOOB thread in CRD TECH area

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

greiswig · **Posted:** Sun Nov 02, 2014 10:30 pm

gmctd wrote:

DTC LIST:

viewtopic.php?f=98&t=40073

Also pics of engine sensors'n'stuff in NOOB thread in CRD TECH area

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

Looked at pics in noob thread, but couldn't find anything germane to the FPS. Interesting that P0192 is not in that list of codes. I found one generic video on testing diesel pressure sensors that seemed to say the signal ground was supposed to be at battery voltage, I.e. +12.8V?

gmctd · **Posted:** Sun Nov 02, 2014 11:37 pm

My bad, then - I haven't revisited since that was posted, but I had added many codes from the DCJ CUMMINS manual referencing those BOSCH CRD codes, identical to the KJ codes but not delineated in the manual

Try downloading the ought 6 KJ FSM from the NOOB site - it has some CRD diagnostics, incl FPS

My Diesel Diagnostics manual is buried somewhere in and locked away out in the 20ft container - guess I needsta do a S&R
mission, now that I'm becoming interested in recovering the li'l KJ

KJ FSM on p8W-30-35 indicates
- pin 1 Yel\brn stripe as sensor gnd from ECM
- pin 2 Brn\yel stripe as sensor signal varying between 0~5v depending on rail pressure from sensor
- pin 3 Brn\yel as sensor +5v supply from ECM - this may be Blu\red stripe

Most KJ engine sensors use +5v VCC supply from ECM - ECM uses +12v to generate sensor voltages

FUEL PRESSURE SENSOR can be seen in the 1st few NOOB pics adjacent the lowest of the arrows pointing to the MAP sensor

Mike92104 · **Posted:** Sun Nov 02, 2014 11:48 pm

viewtopic.php?f=5&t=80488

greiswig · **Posted:** Mon Nov 03, 2014 12:16 am

gmctd wrote:

My bad, then - I haven't revisited since that was posted, (SNIP)

KJ FSM on p8W-30-35 indicates
- pin 1 yel\brn stripe as sensor gnd from ECM
- pin 2 brn\yel stripe as sensor signal varying between 0~5v depending on rail pressure from sensor
- pin 3 brn\yel as sensor +5v supply from ECM

Hey, no worries, man. I am grateful for the help!

My harness colors just do NOT match that. I don't think I have that set of colors on any connector I can see in that section of the harness. I would have remembered for sure if one of them had two of the same color scheme. Although the blue/orange and blue/red I saw in mine might actually be the same, I suppose. Are those for a 2005, or some other year?

I'll take a look at the 06 FSM as you suggest. And thanks again.

gmctd · **Posted:** Mon Nov 03, 2014 12:26 am

George, go back and revisit my post for updated data - I always begin editing for spelling, clarity, added info, etc, with intent to keep pertinent data within a single post - it's always less effective when scattered over invervening posts, and will not show the forum "Last edited" flag unless another post follows mine

Wire coloring is highly depedent on freshness - time, mileage, heat, petroleum fumes, etc quickly serve to deteriorate the vinyl insulation, sometimes rendering the colors indistinguishable and unrecognizeable - fresh colors in NOOB pics show
Yellow\brown
Brown\yellow
Blue\red

My ought 5 shows deteriorated
Yellow\brown
Brown\yellow
Brown\yellow

greiswig · **Posted:** Mon Nov 03, 2014 1:57 am

Okay, well...it makes me wonder if I just flat have the wrong connector on there. But there doesn't seem to be anything nearby with the same number of terminals and the same configuration.

Here is a shot showing what I think we are talking about. Looking back along the right side of the rail, you see this in foreground (FPS?) with the MAP behind it. And the colors don't look faded or anything, but are pretty clearly how I described them.

Totally confused now...

But if this is the sensor that is throwing the code, it looks to me like it has the only connector on it that is nearby and the right format. So either moving the harness broke a wire or wires, the sensor coincidentally went bad while the rail was out, or this circuit somehow depends on some other wiring that I don't yet have plugged in.

gmctd · **Posted:** Mon Nov 03, 2014 3:50 am

That's correct for the FPS, but I see only three (3) 3-wire connectors from the ECM: FPS, Camshaft Position Sensor, and Oil Pressure Sensor, none with matching colors to your picture - also, each connector generally has some type of keying function, such that none will mate to any other

What year-model is your KJ with Blu\red, Blu\yellow, Brn\yellow wires

Head gasket change, no start, P0192

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