Loss of power when accelerating, P0087 P2293 P310B

[edusson]

To the point

Car started hesitating when WOT few weeks ago (maybe once a week). At the time threw the P0087 P2293. Took it to the dealer scared of the cam follower but it was ok. They said I had also P2294 pointing to the hpfp but didn't do the job with them.

Changed later my spark plugs and the problem seemed to go away but came back again a week later. Same codes. Today I changed the fuel filter and problem still there. Still P0087 but now I get P310B. Weird 2293 is gone. The only way to get a 2294 is if I unplug the N276 (regulator valve) but it is plugged (don't ask how I found out XD).

No apparent problems on start-up or idle, only when pushing the gas. It's been very cold weather and today was very warm. No difference. Cabling seems fine.

Plotted few parameters (bought an OBDEleven for this, sorry I cheap out, but doesn't do too bad):

Not sure I choose the right ones (new on this). In the pic you can see:

• RED: Group 1 - Field 1 - RPM (I divided it by 10 so it is easier to see)
• GREEN: Group 2 - Field 2 - Load (%)
• VIOLATE: Group 103 - Field 1 - Low pressure (bar) (I did some math on it to zoom in and make it more visible, so, don't look at the Y axis for values, just the numbers I wrote on the line)
• LIGHT BLUE: Group 106 - Field 1 - High pressure (bar)
• DARK BLUE: Group 106 - Field 2 - In-tank (LP) fuel pump duty cycle

To me the first time I push the gas after starting up the car, everything was fine. RPM up, HP up, LPFP duty cycle up but pressure (LP) same. When I let go the accelerator, one can see the LPFP drop duty cycle for an instant and then back to normal (50%). Note that it is something that happens even on the next "wrong operation" cycles. Then, when I step for 2nd time, things go wrong. HP seems to try to follow but then starts dropping and as such ECM asks the LPFP to work harder. LP raises immediately and never gets back. Only for an instant when I let go the accelerator.

So, who is the suspect here? I think the sensors are ok but somehow HPFP is not doing its job. Not sure why LPFP gets stuck high, though (obviously controller must be asking but why...).

So I got an HPFP and may put it tomorrow but wanted to save the money (return it) if this wasn't the case... I am just running out of weekend

Thank you everyone!

[2007 MKV (2L FSI)]

 

[GTI's]

Maybe post up this log at https://malonetuning.com/ and also do a pull in 3rd gear and at idle. This is a log of a pull in 3rd gear with a car FSI that has no issues. https://log.malonetuning.com/chart/...DrcONQ8Klw6xLasKPw6zDpMO9CcKywpchwqXCqwAAAA== and at idle https://log.malonetuning.com/chart/...Ow4rChsOVS8Kbwp8Ow7JfwqnCoMO2CUrCuMK8YH8BAAA=

Would be nice to see specified and the actual reading for pressure instead of just the actuals

 

[edusson]

Nice site! Thank you!!
Here is the previous log.

I just got the idle, which looks pretty much like the one you sent (the start-up and stop of the engine is also captured...).

For 3rd gear pull I am guessing you meant rolling on the streets, so, here it is. But somewhere read that the ECM may do different depending on the gear position (even revving the car up with the clutch pressed), so, just in case, I took this other one. Sorry if that is just dumb! XD

Just took this data. Sorry for some of the overhead (still learning what every field is...). Haven't really analyzed it but thought I would send in the meantime. Will get back.

Thank you!

 

[GTI's]

It appears that you have an issue with the HPFP based on the pull in 3rd gear from a roll.

 

[edusson]

Thank you! Just for my learning (skip if busy ), I guess you are saying this because of the HP (red) drops away from the commanded (blue) at the instants marked in red (3s, 6s and 10s):

Certainly can't be the pressure sensors because drops (even on other logs) seem to happen only when I'm pushing it, and sensor can't know that I'm doing that...

Still a mystery to me why the LPFP is stuck at full load (black line). It seems to be because the ECM is asking it to increase the pressure to 5.3 bars or more (green line) and pump is always below (~5.1). Maybe because of having to do the work of the HPFP?

Also at second 22, the ECM seems to be saying give me max and the controller drops the duty cycle for a second. Looks strange but maybe some kind of protection...

But anyhow, enough research! As soon as stops raining here (in few days), I am putting the new hpfp... Will let you know if this did it! Thank you again!

 

[vwengineer]

If the LPFP doesn't hold then the HPFP will not be able to hold the pressure, it doesn't mean the HPFP is bad. Did you check the duty cycle of the LPFP at idle? Is it lower than 70%? Did you already replace the fuel filter?

What I see in your case is a problem with the low fuel pressure line, your duty cycle is at 90% all the time (it's also the maximum duty cycle of the pump).

I diagnosed a similar problem on a TT 3 RS, however in that case, the LPFP was dropping to 1.8 bar under very high load while the HPFP only gave 6 bars vs 150 requested. Turned out to be the pump control module.

 

[GTI's]

If the LPFP doesn't hold then the HPFP will not be able to hold the pressure, it doesn't mean the HPFP is bad. Did you check the duty cycle of the LPFP at idle? Is it lower than 70%? Did you already replace the fuel filter?

What I see in your case is a problem with the low fuel pressure line, your duty cycle is at 90% all the time (it's also the maximum duty cycle of the pump).

I diagnosed a similar problem on a TT 3 RS, however in that case, the LPFP was dropping to 1.8 bar under very high load while the HPFP only gave 6 bars vs 150 requested. Turned out to be the pump control module.

The idle was posted in post #3 https://log.malonetuning.com/chart/...Zw60RJkMLF3Ilaz5ywqMeVQbCpcO0A28LKjPCmQAAAA==

 

[edusson]

@vwengineer Changed fuel filter on Saturday. FF877DL from Duralast, rated 6.4bar (instead of 6.6, didn't realize till I had placed it). DTC went from P0087/P2293 to P0087 and P310B (sometimes). The P2293 has never come back and it was quite consistent before... Only other thing that I did by mistake in between was to run the car for 5-10s without plugging the HPFP regulator (then got the P2294 which went away after plugging it).

On the LP, I checked all the logs and looks like it follows the commanded quite well, but it has hard time getting above 5.2bar or so, even when the commanded is 5.8 (when all those cuts are happening). Nevertheless, reading this seems to say that 5 is the upper limit so maybe the ECM is asking because feels the lagging but there is nothing the LP can do :iono:

 

[edusson]

And just one more log to prove the point:

@113.713s the HP starts to drop below the commanded and the LP is actually a bit above (maybe trying to compensate). LPFP load at 45%.
Then HP crashes instantaneously 114.355s (regulator valve not kicking in?) even while the LP is holding. All the way to 117.517s the LPFP seems to be doing its job (above the commanded) but the HP still low. Finally, an instant later, @117.743s, the HP recovers while the LP actually suffers a set back. To me that makes the ECM shoot up the commanded, which actually the LPFP tries to follow/follows (see yellow till 120s).

It is actually very nice to see these graphs. :drool:

The only other thing I could think off is that the relay controlling the HPFP is failing, but I think it wouldn't just fail when I push the gas (someone could argue the same for the HPFP...)

In that sense (you can stop reading here but just in case it helps anyone else looking into similar problem) I would have to re-do the stuff below:
According to this service bulletin should be J757? Not sure I understand those instructions.
Also according to this technical bulletin looks like I should hear a click but I don't (honestly not sure if the OBDEleven/myself is doing this right).

 

[GTI's]

How long have you had this car? What have you done to it lately?

Replace the fuel filter with a 6.6bar, clear all fault codes and see what comes back.

When and if you do the idle log again have the car warmed up and only capture the car idling, do not want to see the effect of cold or warm engine start that would change LPFP function during that time period. Your posted log at idle at the end before shutdown shows LPFP DC in the 40% range which is Ok.

Your log in 3rd gear shows your HPFP is not meeting the specified value several times and your LPFP is trying to help with that issue. You should see a fault code once you meet the DCY frequency.

For your P130B fault code VW did have a RVU and TB for the G410 sensor if you change it out get it from VW.

The J757 relay does provides power to N276 but it also provides power to other parts of the engine and if it was an issue you should be seeing other fault codes for those items.

Keep in mind that the FSI and TSI are not the same engine and that the TB you posted is for the TSI not your FSI. You can still do an output test of the N276 with the engine off, running the test you will hear it click on and off until you stop the test.

You may also want to take a look at https://www.golfmkv.com/forums/golfgoodies/mk5golfengine.pdf for more fueling info.

 

[edusson]

Note: Really appreciate your help but don't want to waste your/others' time. I think we both feel this is HPFP and plan to replace it as soon as weather clears out. I'm following through with all these for my learning and for any others that could benefit of it... so, will just keep posting

I got it brand new in 2007 and it is stock, no mods. Only recent work was unrelated (driver side axle... a week before problem appeared...) After problem appeared, I did spark plugs and filter.

On the idle, here it goes. This was after driving for 10min (and few power cuts along the way). I believe one of those triggered the full LPFP load. Resting there for 5 minutes didn't get the load to go down. But actually I had a run from yesterday (exact same itinerary) and the idle shows in the end as normal (because when I got to idle LPFP load was ok). So, I have the feeling that once you are at idle, whatever condition is triggering the ECM to get out of that mode, it doesn't happen.

Your log in 3rd gear shows your HPFP is not meeting the specified value several times and your LPFP is trying to help with that issue. You should see a fault code once you meet the DCY frequency.

Fully agree. Beyond that, if you look at instant 117.243s in that last log I think that I am getting the LPFP maxing out as a reaction to the LPFP going down when the HP actually recovers (you can see it deeps >0.4bars in 200ms so my guess is that the ECM sees that and reacts, maybe even throws the P310B?). Does this make sense? Will the pressures work out this way?

One mystery still is what makes the LPFP go down back to normal. When the ECM decides enough is enough...

BTW, just to make sure, the P0087 code is for HP being low, right? Not the LP. Says here. Unfortunately the freeze frame from OBDEleven (PRO) is nowhere to be found...

For your P130B fault code VW did have a RVU and TB for the G410 sensor if you change it out get it from VW.

Great tip!! Thanks!!

And thank you too for the TSI vs FSI (I had not realized) and for the pdf! Through OBDEleven didn't hear the solenoid but may be doing it wrong. Can one just apply the battery voltage to the solenoid? But anyhow, the pump seems to work most of the time so, probably not a good test.

 

[edusson]

Alright alright
So, I got stuck trying to pull the LP hose from the HPFP. I had everything else out but I think I needed the hose clamp pliers. And didn't want to take the risk of pulling it out and then not being able to pull it back in, so, I put everything back in and start calling guys till I found one that would do it for me for $100. Sure, the pliers are cheaper but thought that was a fair price and found someone I can work with in the future.

Back from there and... IT IS FLYING :headbang:
Here is the log. After about 10min driving you can see two 3rd gear pulls almost identical in the middle (20s, 50s) and the idles at beginning and end.

HPFP following specd nicely. BUT, what's up with the LPFP? Still running at full load for a while. Does it make sense? I am afraid that I may still need to fix something or pump will just burn out although I got no codes... Unfortunately I got my OBD after the fuel filter replacement, so, got no records before that, but it sounds very strange that the filter (for .2 bars on the regulator, which never hits) would do this, isn't it?

Silly one but what adaptation would do for the LPFP?

Regardless, thanks a lot GTI's and VWEngineer!

 

[GTI's]

This video will show you how to do it yourself next time.

https://www.youtube.com/watch?v=5CD6obyhZmg

The Hpfp looks fine but the DC for the LPFP seems high. Do a log of just that at idle after coolant temp has reached at least 80C.

"Group 106 or 231 just the fields are different
[Go!]

Field 2: Fuel Rail,Pressure (actual): (A value ≈ 35 to 55% is considered normal at idle)

A value ≈ 55% to 60% could be considered as an indication of a low fuel pressure concern

A value above ≈ 60% to 70% usually indicates there is a failure or restriction

A value fluctuating ≈ 35% to 95% may indicate an intake fuel pump failing Causes of low pressure can include:

Damaged/restricted fuel lines

Fuel filter issues including restricted/clogged or incorrect part number (wrong pressure relief value)

Faulty in-tank fuel pump and/or in-tank fuel pump controller. (With critical parts, we encourage customers to use Genuine Factory parts from the dealer's parts department.).'

From RT Checking Fuel Pressure

http://wiki.ross-tech.com/wiki/index.php/2.0l_TFSI_(AXX/BGB/BPJ/BPY/BWA)



"Silly one but what adaptation would do for the LPFP??"

When you replace the LPFP or LPFP module needs adaptation / basic setting

You should see a field that show status like ADP. OK

 

[edusson]

Yeah, I had watched that video like 10 times... To remove it, one of the issues I had is that the clam on the pump side of the hose was facing the outlet fitting (!?!) but maybe if I had used the WD40 and/or unscrew the outlet fitting... Then I tried on the other side of the hose, by the metal lines and managed to remove the clam but didn't pull the hose out. My concern was that in either side, after I take it out I didn't know how hard was going to be to put it back in and it look really hard in either side. Didn't want to get stranded. FYI, my mechanic said he did the one by the metal side and used the clam pliers...

And yep! Had seen that link too. There is a filter out there with a 4bar limit. I can see how that would be a problem. But the 6.4 bar when the pressure barely reaches 5... The filter is actually sold in Autozone as the right one for my car. It seems that the 6.6 is also more related to hot starts (I recall reading somewhere). Anyhow, will have to try if I run out of options. Will do the log you said...

My question on adaptation is what exactly does. Is there a link that explains this? Like is it trying to calibrate something? Why is needed for a pump but not for a filter or something else... I have seen somewhere the procedure to do it (like start the car, go for 4 miles...) but still don't understand what is happening there. And what's more, if it says ADP OK, does it mean, there is no point on running again adaptation?

 

[edusson]

Well, just to close on this, I did several runs:
On secondary streets
On highway Actually it is street-highway-street.

In both cases you can see that the LPFP is working fine, around 40-50%. There are some idle periods in between and in the end looking normal too. Never goes beyond that. So, everything looks good to go!

My thought is that maybe in the past the ECM noticed something was wrong and pumped the LPFP to support the ride, regardless of anything, just being preventive, but that after few days the ECM has realized everything is fine now so it stopped doing that and use the "normal" mode. Just a guess.

There are still things that I don't understand, like somehow the commanded is constant but the pump duty cycle drops when I let go the gas. I am not sure how the LPFP knows that if the commanded is not changing... Maybe the LPFP controller can sense the LP? Also the LP goes up when the duty cycle goes down. Anyhow, time to move on with my life... Cheers everyone