Woes with a 2004.5 LLY Dmax repeated P0089 Fuel pressure regulator codes.

@madhawg Check this out.

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Bosch CP3 Injection Pump Info

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FUEL CONTROL ACTUATOR aka Fuel Pressure Regulator

DESCRIPTION
The Fuel Control Actuator solenoid valve is located on the back of the front cover of the high-pressure pump. The solenoid is pulse-width modulated by the ECM and meters the amount of fuel that flows into the high-pressure elements inside the high-pressure pump.
The solenoid is inactive up to 30 seconds after IGNition switch is initially keyed to ON position to allow maximum fuel pressure to the fuel rail during cranking and start up. ECM assumes FCA valve control when CPS signal and rail pressure are within acceptable limits

OPERATION
The Fuel Control Actuator solenoid valve is a pulse-width modulated valve that controls the amount of fuel sent or delayed to the high-pressure pump elements inside the high-pressure pump. The ECM determines the fuel pressure set point based on engine sensor and rail-pressure inputs. If the actual fuel-rail pressure is too low, the ECM commands the solenoid to allow more fuel to flow to the high-pressure pump. This minimizes the difference between the actual fuel-rail pressure reading and the set point. The ECM will also operate the solenoid to delay fuel, reducing flow-rate, if the fuel-rail pressure becomes too high.
The FCA valve is commanded open by the ECM to allow the high-pressure pump to build maximum pressure
(1600bar, 23,206psi).
Thus, rail fuel-pressure can be increased or decreased independent of engine speed
 
As far as I remember that only applies to ensuring sufficient prime when starting. It should bleed off excess pressure immediately. In simple terms its just a metering device. The fuel strategy for a given ECT like SRGN mentioned also plays a role. If sufficient fuel is present to cause fuel knock, something is out of sync.

Had another thought recently, that 11000 number you mentioned in the OP is psi correct? Just want to be sure because 11000kpa is only about 1600 psi which I doubt it would run that low.
 
Another thought...have you ever checked the API of the fuel that;s currently in it? Thought of that when you said it started fine with that warm weather we had for one day
 
madhawg said:
As far as I remember that only applies to ensuring sufficient prime when starting. It should bleed off excess pressure immediately. In simple terms its just a metering device. The fuel strategy for a given ECT like SRGN mentioned also plays a role. If sufficient fuel is present to cause fuel knock, something is out of sync.

Had another thought recently, that 11000 number you mentioned in the OP is psi correct? Just want to be sure because 11000kpa is only about 1600 psi which I doubt it would run that low.
Click to expand...

This is what the scan tool shows, Snap-on shows same reading.

180000 kpa = 26106 psi it's actually maxing out

I will double check this when I test again tomorrow. Been sitting since Wednesday

See below for pic forgot to add to this post
 
That's likely KOEO and it all looks normal if so. Battery looks low though

**I hate metric with a passion. Never could correlate the 2, which is always why I set the units to english on the scanner or used a conversion chart.
 
Couldn't wait till tomorrow.

Fired it up, no codes. 29 degress outside air temp.

First set of pics KOEO










Running








 
(y) (y) (y)
Now we're talking...you did excellent with those shots of data. Everything looks good though, no surprise its running good this time around. Brings me back to maybe something floating around in one of the rails? But that's still just a WAG.

Before I nodded off last night, I got to thinking about what I posted and need to clarify something. When I mentioned API, which is what we always called it and stands for American Petroleum Institute. What I was actually talking about was what the specific gravity of the fuel was. You use a special hydrometer to measure it. Spec is 30-42 with ideal being between 34-38. Probably not a concern for you now since it started ok at 29°.
 
AWESOME, ya finally fixed it!!:p

Actually doesn't surprise me. I've seen plenty odd ball problems fix themselves. Kinda makes me think it WAS some junk in the rail and it dissolved and passed through.

Keep this thread updated if it acts up again.
 
madhawg said:
AWESOME, ya finally fixed it!!:p

Actually doesn't surprise me. I've seen plenty odd ball problems fix themselves. Kinda makes me think it WAS some junk in the rail and it dissolved and passed through.

Keep this thread updated if it acts up again.
Click to expand...

LOL This thing is possessed by the devil himself.
Put 41 miles on it yesterday, ran perfect.
Almost home and I decided to get on it and BAM P1093 and limp mode.

Pics I grabbed before I shut it off last night.











 
That's odd that Des and Act read the same unless that was after the fact. Not completely familiar with a Solus. Are those screens during or right after the event, or from Freeze Frame/Failure Records if it has that option?
 
madhawg said:
That's odd that Des and Act read the same unless that was after the fact. Not completely familiar with a Solus. Are those screens during or right after the event, or from Freeze Frame/Failure Records if it has that option?
Click to expand...

That was after I got home, left it running and hooked the Solus up to it.

After I talked to you I went out and started it. P0089 came back.
I couldn't change the fuel pressure like you asked me to previously with the Solus.
Fuel pressure was way high and I could hear the injectors hammering, shut it off and re-started it and fuel pressure returned to normal
and sounded like it should.
Cleared code but haven't driven it.

Not sure how fuel temp could be 72 degrees, it got down to 19 degrees last night and I had just started it.





 
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That shutting it off and restarting corrects it has me baffled. That indicates you're resetting the PCM when you do. I know you said you tried another...was it a new or a known good unit?

Good to see the fuel rates while its fuxed up. That tells me the PCM isn't commanding the fuel that high, if anything its trying to lower it back to 42. Plus with the APP at 0%, no erroneous throttle input.

Another oddity is the fuel temp. With 19° ambient, it should be fairly close to that. Maybe the sensor is skewed or possibly that C107 connector on top of the LH VC, since the circuit runs through it. Did you ever replace the fuel temp sensor in the LH rail?

Since we can only see the commanded state for the FPR, I wonder if its not responding. Meaning the command is issued, but its not affecting the regulator due to weak or loss of signal. But that contradicts why the rail press is that high unless it stayed that high when you put your foot in it. Again, that C107 connector comes to mind since it runs through that. As I previously mentioned...C107 is problem prone for terminal fretting. I know you said you and SRGN checked all the wiring, but maybe the circuit was intact at that time??...that's all I can think of. I'll see if I can get a bunch of terminals for the C107 from my buddy at the dealer this week. Or you could just cut the wires for the affected circuits and splice a jumper for each one to bypass C107. Won't hurt anything other than having to cut the wires if you ever need to remove the VC.

Meanwhile, I'm gonna see if I can get a hold of the other tech who did diesels with me at the dealer. He left last year and haven't spoke with him for a couple years, but I still have his number. Maybe he can shed some light on this. I wouldn't be surprised if the first thing he says is C107
 
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madhawg said:
Another oddity is the fuel temp. With 19° ambient, it should be fairly close to that. Maybe the sensor is skewed or possibly that C107 connector on top of the LH VC, since the circuit runs through it. Did you ever replace the fuel temp sensor in the LH rail?
Click to expand...

Haven't replaced the fuel temp sensor. ACDELCO 97224993 is $27 on rockauto.
 
madhawg said:
That shutting it off and restarting corrects it has me baffled. That indicates you're resetting the PCM when you do. I know you said you tried another...was it a new or a known good unit?
Click to expand...

I was told it was a working ECM, I could try it again now that I have a baseline of what is happening.

I think the FPR is working and good because in the past with the fake and bad FPRs I couldn't even drive the truck.
It had no power at all and clouds of smoke out of the tailpipe.
 
The smoke is typical with a faulty FPR. Though I'm kinda surprised it isn't/wasn't smoking when the rail press went haywire...or was it?
 
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