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No fuel pressure with new parts - 2006 BPY

S

ShadowSplicer

Independent AMSOIL Dealer
Location
Campbell, CA
Car(s)
Candy White .:R32
Hey all!

Posting again about my GTI (2006, BPY). After figuring out the timing belt and getting the timing set, it's been driving around great!
Then suddenly, it stopped working - stranded me 30 miles from home. Only thing I can think of being wrong is the fuel delivery system, which I've replaced a bunch of to narrow down the issue (and because some bits were original to the car), with all OE parts.

The car takes a second or two to start, and then sputters and runs unevenly like it's misfiring. Checked my fuses, checked my HPFP, cam follower and intake cam, fuel filter is pretty new, and after that I flat out replaced my LPFP and sending unit connected to it since they are both prone to failure (and still original to the 140k mile car). No luck.

I was also told to check sensor G247 on the fuel rail, and replaced that as well for good measure (again, 2 revisions behind). No luck, but I noticed something very confusing.
With the sensor unhooked, the car idles great. The fuel pressure requested is the same whether the sensor is unhooked or not, but runs better when the sensor isn't connected and the supplied fuel is near nothing. Near nothing, but steady – is that the reason it is running well?

So my questions are:
What else can cause a super low supplied fuel pressure?
The requested/supplied fuel pressure measurement is from the HPFP, correct?
Can I get details for checking the voltage supplied to the LPFP, to make sure it's actually getting a signal?


When I get home, I'll post the graphs I made and the logs from VCDS.
The vehicle wasn't warmed fully, so the idle was high. I didn't capture the RPM because I'm dumb, but I will be taking more logs off of your suggestions.
The blips in the logs are from me tapping the accelerator, idles around 700, topped at 2500 with throttle.
 
ROH ECHT

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Waiting to see your codes if any are stored. You replaced a bunch not having any codes to go off of. $#!@T...might be a bad wire to the hpfp. I would certainly look at the codes first....second would log some fueling data, and more, if necessary. I believe the amps to the lpfp are 16 to 17 amps maximum from the control module.
 
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S

ShadowSplicer

Independent AMSOIL Dealer
Location
Campbell, CA
Car(s)
Candy White .:R32
ROH ECHT said:
Waiting to see your codes if any are stored. You replaced a bunch not having any codes to go off of. $#!@T...might be a bad wire to the hpfp. I would certainly look at the codes first....second would be log some fueling data and more if necessary. I believe the amps to the lpfp are 16 to 17 amps maximum from the control module.
Click to expand...

Yeah man I'll have to snag those tomorrow after work, got too busy today. I'll pull some more logs, too.

Honestly I've been working on it for 6 months with everything breaking on me, so most of the time I encounter a part that's original to the car that is related to a failed system, I replace it if I can find a good price on it of a newer revision. I know it's not efficient problem solving, but it's needed for my sanity in the long run.

Thanks for the response man, I'll get back to you.
 
ROH ECHT

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Yes, post the codes if any remain and have not been cleared in the past...do not delete or clear them just yet. If you want...go on and copy and paste them and you can clear all codes. I say do not clear the codes because you may need them stored if you need to have a VW tech look it over if all else fails.
 
S

ShadowSplicer

Independent AMSOIL Dealer
Location
Campbell, CA
Car(s)
Candy White .:R32
Okay guys, just went to pull more codes and take a better value log.

Something that I noticed was that I can't hear the LPFP priming at all when I open the door, OR when turning the key. I'm wondering if this is my issue after all - what all can I check in the LP system?

I have yet to check the voltage to the LPFP, since it's hot and I'm getting over being sick. If the pump isn't getting voltage or signal to pump fuel, would it be possible that my no/low pressure is due to the HPFP having to draw the fuel up through the lines?

Here is the log showing fuel pressure.

HTML: 
3 Faults Found:

000768 - Random/Multiple Cylinder Misfire Detected 
               P0300 - 001 - 
             Freeze Frame:
                    Fault Status: 01100001
                    Fault Priority: 0
                    Fault Frequency: 1
                    Reset counter: 255
                    Mileage: 235995 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 02:18:41

             Freeze Frame:
                    RPM: 1165 /min
                    Load: 41.6 %
                    Speed: 0.0 km/h
                    Temperature: 30.0°C
                    Temperature: 29.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 13.208 V

000772 - Cylinder 4 
               P0304 - 001 - Misfire Detected
             Freeze Frame:
                    Fault Status: 01100001
                    Fault Priority: 0
                    Fault Frequency: 1
                    Reset counter: 255
                    Mileage: 235995 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 02:18:46

             Freeze Frame:
                    RPM: 1187 /min
                    Load: 40.0 %
                    Speed: 0.0 km/h
                    Temperature: 30.0°C
                    Temperature: 28.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 13.716 V

008851 - Fuel Pressure Regulator Valve (N276) 
               P2293 - 002 - Mechanical Malfunction
             Freeze Frame:
                    Fault Status: 01100010
                    Fault Priority: 0
                    Fault Frequency: 1
                    Reset counter: 255
                    Mileage: 235995 km
                    Time Indication: 0
                    Date: 2000.00.00
                    Time: 02:18:52

             Freeze Frame:
                    RPM: 1184 /min
                    Load: 40.4 %
                    Speed: 0.0 km/h
                    Temperature: 31.0°C
                    Temperature: 28.0°C
                    Absolute Pres.: 990.0 mbar
                    Voltage: 13.589 V


Readiness: 0110 0101
 
S

ShadowSplicer

Independent AMSOIL Dealer
Location
Campbell, CA
Car(s)
Candy White .:R32
No responses so far, still scratching my head here with a broken GTI...

Tried running it with the LPFP sensor unplugged completely, and it just died out. Defeats my idea of the HPFP drawing any fuel straight from the tank. Still not sure where to check, LP or HP side.

One more development: can't run any tests at all. I had forgotten to mention it before, but again today when I tried and run basic tests through VCDS, I got stonewalled by the ECU. "Refused by control module: 7F 22 22" I can't run any tests, even in other areas. I can still pull values and data, just not run tests. Even if I force clear codes and try to leave it off and try again, (or even try running again and trying it), just doesn't work.
Previously before this issue, I could run tests however I wanted to without any issues.

Help! Even dialogue would help, not just looking for an easy answer.
 
ROH ECHT

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Before I answer your questions posted in the 1st post...I just saw you posted data 2 posts up...so I need time to look... ←this was added after all of this ↓..LOL

I am not on here daily as I once was, but I will try helping. Usually when the code is P2293...it is due to the regulator reporting its inability to produce requested pressures. So, means restricted on the low side, or the cam driving the hpfp is failing due to reduced stroke or worn tri-lobe or a destroyed cam follower. Could also be worn hpfp piston retainer nut seals leaking gas into the oil.

Can you explain the process for; "...checked my HPFP, cam follower and intake cam..."? Meaning, you looked at them? Have you a way to compare target to actual pressure data? Is actual able to stay within ±15 bar of the target pressure?

What is the low pressure pump's target to actual pressures look like? I know you said you replaced both the lpfp and controller, but is the data showing low pressures within specs...actual to target pressures? Does actual remain over 4 bar and within 0.5 bar from the target?

Best guess is either the low side is unable to provide proper pressure or it's reporting false data due to real pressure is insufficient or a failing sensor...or the high side is unable to produce proper pressure or has a failed sensor. This means look and real-time data if safe to do so. If pressures are within specs...sensors are likely good and it is mechanical. If not within specs, it could be sensors reporting badly or it's failing mechanically.
 
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ROH ECHT

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
OK...looked at the data.
Obviously the CF still has the black DLC and is solid, right?

So, your actual rail pressure being so low is most likely due to the tri-lobe being worn on the intake cam.
However, if you strongly believe the cam lobes and CF are fine...then your hpfp either has a failed N276 pressure regulator or is leaking at the retainer nut seals and then the oil may smell like fuel. In either case, you need a new hpfp.

There's one more issue; obviously it is not at idle but I see your lpfp/electric pump's duty at over 60% at a low throttle angle as if were in cold sart rev range...so it borders on confusing. What is the data in group 231 at idle only? Look at it when at idle only and hover over the blocks to see the specs and range it should be within.

Group 231 is data collected by the sensor on the side of the hpfp. Group 230 data is the sensor on the rail. I do not believe there is an issue on the low side because there would be stored codes for it as well. So this is communicating the hpfp inability to produce pressures for the rail. Again, it is the cam lobe wear or the hpfp's N276 or inner seals leaking.

OK, The G247; was it selected per your VIN? Or chosen online based on the year make and model? Also...fuel filter is newish. Fuel filter replaced after all of these symptoms started or before? Is it an oem filter 6.6 bar regulator per your VIN or was it ordered online per the Year, Make, and Model? The G247 could be incorrect and the filter as well. But if they are correct, no worries.

My steps would be; check data for group 231 at idle and if OK...move on to rechecking the correctness of the G247 part number and your VIN...and then another proper inspection of the tri-lobe. Finally, replace the hpfp so to have a new retainer nut seal and pressure regulator-N276. Electrical for the N276 is apparently fine.
 
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S

ShadowSplicer

Independent AMSOIL Dealer
Location
Campbell, CA
Car(s)
Candy White .:R32
Good news, the GTI is running again!

Long story short ROH, I checked my fuel filter was correct, double inspected the cam follower and tri-lobe, and the oil smelled more like fuel than usual. Decided to order a pump to get the new sensor and rule out all other issues you had mentioned.
I replaced the whole pump with a factory one (through DAP, sale for $250), and instantly everything was running amazingly well. Better than the car has ever driven!

So hopefully when I check all my fuel pressure values and run some tests, I'll have a good report! But for now, seems happier than ever.


I appreciate the time you took to answer my questions ROH, and I'll definitely post a follow up if anything seems odd.
 
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