Need to fix oil pump issue. Maybe derating/shutting down because of low oil pressure? Not sure if DMAX does that though.
No fun at all.

 

Please post the LP5 version of P0016 so that we can see what that says. Do you have any other codes currently?

I can see I have about 8500psi on the high side of the fuel rail.

I believe you told me that was at idle, correct, not driving down the road?

 

Ok guys, I talked with a diesel injection shop last week about my issues. They believed that when the fuel pump was in the wreck that it sent metal to my injectors and said they needed replaced.

I have removed every fuel line, ran it through my ultrasonic cleaner, pumped mineral spirts at pressure through all of them. Everything back on and together with 8 new injectors. Same problem.

Can barely get it to run and the fuel rail pressure is between 7,000-11,000 with it barely idling. When it jumps up, it just dies.

I put a new "take off" high pressure pump on it. Do I have a bad high pressure fuel pump?

Hard to diagnose the other stuff when I can't get it to run...

 

Did u put a new fuel pressure regulator on it with the different pump? Or something is telling the computer to up the rail pressure.

 

From Chevrolet-GMC Diesel Diagnostics about LML engines:

Verify the fuel injector return line pressure is greater than 3 BAR (see “Fuel Injectors” for more information). Buy LML Injector Return Rail

You would inject about 50 lbs of compressed air into the injector return line while cranking to create this pressure.

The high pressure fuel is supplied to the fuel injectors (1) through separate high pressure pipes. The fuel injectors supply fuel directly to the combustion chambers of the engine. The fuel that is not injected into the combustion chamber is used to help lubricate and cool the injector and is routed back to the fuel tank. The fuel injector return line pressure regulator (14) maintains fuel pressure on the return side of the fuel injectors. This is required for proper fuel injector operation. In the event the vehicle runs out of fuel, a check valve (11) in the exhaust after treatment fuel injector (10) supply line opens, and the fuel supply pump backfills the return side with fuel. (Courtesy GM)

I don't know if this is the case with LP5 engines. Perhaps you could ask your local shop about this.

 

I used the fuel pressure regulator that came with the new pump. I have had it off and I can put 12V power to it and see that it moves in and out. I tested the original one and it work the same way.

Would a high pressure pump be able to put out too much pressure? I have done the flow test on the return side and that is within the limits. The AllData says if that comes back within tolerance that the high pressure pump should be replaced.... But it's brand new!

 

The AllData says if that comes back within tolerance that the high pressure pump should be replaced.

Please look at this again. Usually if within tolerance, it would indicate NO PROBLEM, not replace pump.

 

The only thing I have not done is the shop towel test in the glow plug holes.... I guess that will be next, then a high pressure pump as suggested at step 25.

1. Engine » Idling
2. Perform the following procedure/test: Fuel Injector Balance Test
   Verify the procedure/test passes.
   • If the procedure/test does not pass
     Replace the component that failed the test: Q17 Fuel Injector
3. • If the procedure/test passes
4. Ignition/Vehicle » Off
5. Note:
   • In order to perform step 5–8, the fuel temperature must be greater than 10°C (50°F) or misdiagnosis may occur.
   • Leave the electrical connector connected.
6. Disconnect the component: Fuel Return Hose @ Q18B Fuel Pressure Regulator 2 & Plug the fuel return hose(s) in order to prevent leakage.
7. Install suitable hose to the component: Outlet @ Q18B Fuel Pressure Regulator 2 & Place the other end of the hose into a suitable container.
8. Engine » Idling — Until air is purged from the hose
9. Engine » Idling — For 15 s
   Verify the container contains less than 15 mL (0.5 US fl oz)
   • If 15 mL (0.5 US fl oz) or greater
     Replace the component: Q18B Fuel Pressure Regulator 2
10. • If less than 15 mL (0.5 US fl oz)
11. Ignition/Vehicle & All vehicle systems » Off
12. Install the component: Fuel Return Hose @ Q18B Fuel Pressure Regulator 2
13. Remove the component: F86UA Fuse @ X50A Fuse Block - Underhood
14. Disconnect the component: Fuel Injection Fuel Return Pipe @ Bank 1 & Bank 2 — Plug the fuel return hose(s) in order to prevent leakage. Refer to: Fuel Injection Fuel Return Pipe Replacement - Left Side & Fuel Injection Fuel Return Pipe Replacement - Right Side
15. Note: Do NOT use the following tool or the incorrect test results will occur: Remote Start Switch
16. Engine » Cranking — For 15 s
17. Verify the condition does not exist: Leaking @ Fuel Injection Fuel Return Pipe
    • If a condition exists
      Replace the appropriate component: Q17 Fuel Injector
18. • If no condition exists
19. Ignition/Vehicle & All vehicle systems » Off
20. Install the component: Fuel Injection Fuel Return Pipe @ Bank 1 & Bank 2
21. Note: Perform the following test for all 8 components. — One at a time
22. Perform the following steps:
    1. Remove the component: F86UA Fuse @ X50A Fuse Block - Underhood
    2. Disconnect the electrical connector: X1 @ K34 Glow Plug Control Module
    3. Disconnect the electrical connector: E12 Glow Plug
    4. Note: The component must be discarded whenever removed and replaced with a NEW component:
    5. Remove the component: E12 Glow Plug — One at a time
    6. Place and hold a clean shop towel over the component: Threaded Hole @ Cylinder Head — Glow Plug
    7. Engine » Cranking — For 6 s
       Verify the condition does not exist: Fuel On Shop Towel
23. • If a condition exists
      Replace the appropriate component: Q17 Fuel Injector
24. • If no condition exists
25. Test or replace the component: G18 High Pressure Fuel Pump

 

Decided to look in to the front cover to make sure I didn't shear a pin and /or get out of time due to the P0016 code. All good in there.

 

I did go ahead and pin the drive gear for the oil/water pump, so it wasn't a total waist of time. I also installed a new high pressure pump while I had all this apart. Still the same.

I can see that my command pressure matches the actual. So, what is telling this thing to go high on pressure? It is also very erratic. I tried unplugging one injector at a time and no change there either..

 

So, what is telling this thing to go high on pressure?

The most likely thing is the ground or other circuit problems. Must have a complete circuit right? If you were just to unplug the FPR, it would pump at max pressure. Have you changed the fuel rail pressure sensor?

If your truck started or ran at very high pressure, it would sound like an old Ford diesel, very noisy.

 

I still have my P0016 code. For grins, I wanted to make sure my crank wasn't broke. It took a good portion of the hit! I can rotate back and forth and the front matches the back.

I tried the procedure for the crankshaft variation relearn, but it can't be completed because the engine isn't up to temp. But I can't get it to run long enough to get it up to temp. I am able to see data from both sensors and my scan tool does say that they are synchronized...

 

Ron, it is very loud when it does start. I do believe it has very high rail pressure. I'm just stuck on what is telling it to run much higher than it should be

 

Check the circuit for the fuel pressure regulator.

Q18A

Fuel Pressure Regulator 1

L5P

In the engine compartment, in the cylinder head above cylinder 1

—

Q18A Fuel Pressur Regulator 1 (L5P)

Q18B

Fuel Pressure Regulator 2

L5P

In the engine compartment, left side of engine, mounted to the left rear side of the valve cover

Engine Components - Left Rear (L5P)

Q18B Fuel Pressure Regulator 2 (L5P)

 

Ron, I was able to check the circuits from the plug to the ECM on both of the above as well as the sensor on the passenger side fuel rail. All circuits are connected...

 

You followed the instructions in the P0090 document previously posted, correct? When you say in post 16 that they're 'connected', my mind goes to a continuity test. Hopefully your testing method is correct and time to move to something different.

 

Ron, I checked for continuity and for the ohm reading. I get 4ohm on #2 and 3.8 on #1. Tolerance is 2.6-3.0... Both of the sensors are new from the dealer this week and I believe the reading to be close enough tolerance. I also put a test light at each plug at the regulators. Both circuits light up and I am able to watch the test light go bright and go dim when I turn each regulator on and off with the scan tool

 

If the only code I have popping up is the P0016 (crankshaft/camshaft correlation not plausible), I'm going to be digging further in to that. I have verified that I can see each sensor reading. The crank is reading twice what the cam is. My scan tool says the are synchronized. I have went through the diagnostic instructions specified on AllData.

Circuit/System Verification

1. Ignition » On / Vehicle » In Service Mode
2. Verify DTC P0340, P0341 is not set.
   • If any of the DTCs are set
     Refer to: Diagnostic Trouble Code (DTC) List - Vehicle
3. • If none of the DTCs are set
4. Engine » Idling — At normal operating temperature
5. Verify DTC P0016 is not set.
   • If the DTC is set
6. 1. Ignition/Vehicle » Off
   2. Verify the following conditions do not exist:
      • B23 Camshaft Position Sensor — Incorrect installation
      • B26 Crankshaft Position Sensor — Incorrect installation
      • Reluctor Ring — Misaligned @ Crankshaft
      • Timing Belt or Timing Chain — Excessive play
      • Timing Belt Tensioner or Timing Chain Tensioner — Incorrect installation
      • If a condition exists » Repair or replace as necessary
      • If none of the conditions exists » Refer to step 2.

The only thing I can not easily check is the reluctor ring on the crankshaft. No damage was done around the iron part of the block. The rear cover had a small crack in it, thats why I replaced it.

What is the likelihood that the crank reluctor ring has "misaligned" ? Would the best way to take a look be to remove the lower oil pan?

The book pays 4.3 hours, so it doesn't seem complicated.

 

See the attachment. CKP reluctor on my engine right in the front. Yours? I have no idea where it is but ALLDATA does.

 

Ron, mine is in the back. Sensor sets in behind the starter.

 

Thanks. I think now I remember you telling me that. You have to pull the starter or is it more than that?

Maybe this?

Some general info you probably already know, but maybe others haven't seen this:

Some of the engine controls components and their
operation are as follows:
Camshaft Position Actuator System
The camshaft position actuator system is used for a
variety of engine performance enhancements. These
enhancements include lower emission output through
exhaust gas recirculation (EGR) control, a wider engine
torque range, improved fuel efficiency, and improved
engine idle stability. The CMP actuator system which is
controlled by the ECM, accomplishes these
enhancements by controlling the valve timing relative to
piston position.
Camshaft Position Actuator System Operation
The ECM sends a pulse width modulated signal to a
CMP actuator solenoid in order to control the amount of
engine oil flow to a camshaft actuator passage. There
are 2 different passages for oil to flow through, a
passage for CAM advance and a passage for CAM
retard. The camshaft actuator is attached to the front of
the camshaft, and is hydraulically operated in order to
change the angle of the camshaft relative to the
crankshaft position.
Camshaft Position Sensor
The camshaft position sensor (CMP) detects magnetic
flux changes between the four narrow and wide tooth
slots on the reluctor wheel. The camshaft position
sensor provides a digital ON/OFF DC voltage of varying
frequency per each camshaft revolution. The ECM will
recognize the narrow and wide tooth patterns to identify
camshaft position, or which cylinder is in compression
and which is in exhaust. The information is then used to
determine the correct time and sequence for fuel
injection and ignition spark events.
Crankshaft Position Sensor
The crankshaft position sensor (CKP) is an internally
magnetic biased digital output integrated circuit sensing
device. The sensor detects magnetic flux changes of
the teeth and slots of the reluctor wheel on the
crankshaft. The reluctor wheel is spaced at 60-tooth
spacing, with two missing teeth for the reference gap.
The reference gap is used to identify the crankshaft
position at each start-up. The ECM uses each
crankshaft position signal pulse to determine
crankshaft speed position, to determine the camshaft
relative position to the crankshaft, to control camshaft
phasing, and to detect cylinder misfire.

 

I would get a laptop and look at ALL the available PIDs and see if some sensor is way out norms. Something is telling the ECM to command high rail pressure. I just can't think what it might be

 

Would that require a flashed ECM? Im new to the world of these Duramax's.

 

Ron, thanks for that info. I am able to do the same thing with my Topdon 900 scan tool as the Auto Agent 3. My issue is that the engine needs to be able to start and warm up to operating temp. to perform the relearn.

It is unclear to me if the ECM gets its pulse information for the injectors through the crank sensor or the cam sensor. Either way, the ECM is getting information from both sensors, it just doesn't like the timing of them.

I talked with Thoroughbred Diesel again today and we believe that the low pressure side is doing what it should. So, for now, I'll rule out the fuel pump module and lift pump as I'm seeing a consistent 60-62 psi on the low side

Being that my test passed with the fuel regulators I may start looking for an ECM. I have always hesitated when replacing an ECM as 98% of the time, an ECM is not bad. But I have replaced three of them in other vehicles in the last year that fixed the problem it was having.... But the test also passed for the ECM being that I could turn on and off both regulators.

As I tell my kids " You are going to pay for an education one way or another". I'm certainly paying for this one.

 

When you have your scanner hooked up, have you looked at devices/signals that need to allow a start sequence? TCM, trans in park or neutral, brake pedal pressed, those kind of things? I would look at anything you can to see if it makes sense to you or doesn't. Is the ECM, TCM, etc being powered with key on? What can you glean from the start switch positions.

If the problem was the ECM, what is failing in yours? What information is not being correctly produced or acted on?

You've probably been through all of this, right?

See my message to you also.