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High LTFT K04 BPY

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
That's a pretty bad leak somewhere then. I knew a very high short term(MB 033 block 1) after clearing codes points to a leak and can cause the ltft idle to sit at about 2 to 3% once it adjusts...but ouch!

I bet when you finally discover that and fix it the ltft partial will come down dramatically.
Can you list again all you have found or checked? I'm going to go back and read everything again...see what you've replaced or if you smoke tested it etc..
 
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ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
On another note; I drove mine today but was too chicken to floor it. I disconnected the PM3 before leaving the house because the Quantum should perform max target pressure at just 11 amps. I will do the data and full throttle test very soon though. Probably going to sell the PM3...but not removing it until money from a buyer clears in the bank. I just removed the forward fuse and disconnected it from the oem controller for now.
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
No smoke test yet. To chase lean condition I've...
  • Checked all hose clamps from air filter to throttle body. Fixed two big leaks right where turbo meets the intake
  • Replaced MAF
  • Removed oil fill neck
  • Upgraded LPFP
  • Replaced dipstick
Planning to...
  • Replace MAP sensor
  • Replace gas cap
  • Replace n80 valve
  • Replace tank gasket and lock ring
  • Remove zip tie and install OE hose clamp on rear breather tube
  • Replace oil cap
If issues are still present after all that, I'll smoke test to find leak, but the only other big leak points remaining would be...
  • Front PCV and breather tube (have a block off plate currently. No oil build up around it)
  • Brake booster
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
No smoke test yet. To chase lean condition I've...
  • Checked all hose clamps from air filter to throttle body. Fixed two big leaks right where turbo meets the intake
  • Replaced MAF
  • Removed oil fill neck
  • Upgraded LPFP
  • Replaced dipstick
Planning to...
  • Replace MAP sensor
  • Replace gas cap
  • Replace n80 valve
  • Replace tank gasket and lock ring
  • Remove zip tie and install OE hose clamp on rear breather tube
  • Replace oil cap
If issues are still present after all that, I'll smoke test to find leak, but the only other big leak points remaining would be...
  • Front PCV and breather tube (have a block off plate currently. No oil build up around it)
  • Brake booster
How's yours running with the Quantum at full throttle? I did the first full throttle pull in mine today with the 2nd Quantum and it does the same thing...it codes P301b "pressure too low." Not only that, when I first began the pull it went to 30 psi boost so I let off the throttle. Then it wouldn't go past 5 psi boost. Now it is smoking from the exhaust. I swear, today has been the worst. Prior to this I spent hours trying to figure the shipping for the guy in Canada that bought the PM3...and ended up refunding him. I only took it in for all the new stuff to be installed just so everything is refreshed. Not that it ran poorly or anything. I replaced the lpfp with the 1st Quantum and had the shop replace the thermostat, injectors, and oil filter housing and now it won't even run like it did before all this. Bad Sad Day! Not happy right now. I am taking mine into the shop to say, Fix it! Whatever was done has messed something up.
 
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ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
OK, I have some results to report. It seems I skipped a step that may or may not affect the performance of a newly installed pump. That step being;
9 – reinstall the assembly into the fuel tank and attach a length of hose to the outlet of the pump assembly allowing it to drain into a fuel safe container and prime the fuel pump assembly.

After testing everything and replacing the G410 and the fuel filter, nothing changed as it continued to run poorly. Then after swapping the fuel pressure gauge because the one was only working as a compression tester would in showing the peak pressure and not the live...we found a gauge that wouldn't stick at its peak pressure. My tech went for a drive and it had somehow fixed itself. Leaving me to believe it had a sort of "vapor lock" in the system so to speak. My tech, when he got back, said "I don't know how but it runs like a raped ape now."
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
Glad to hear. I also ran adaptation on the tank pump/controller through VCDS. When I first installed the Quantum, cycled accessories several times and had also transferred fuel from the other basket into the Quantum's before dropping in the assembly. Made sure the pump was consistently quiet (full?) before taking it for a spin.

On your step 9 bit, simply cycling accessories should do that since excess pressure gets cycled back to the pump assembly at the fuel filter.

Transmission will be replaced in a month at most. Timing and what not. So will have to wait until then for more testing.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Glad to hear. I also ran adaptation on the tank pump/controller through VCDS. When I first installed the Quantum, cycled accessories several times and had also transferred fuel from the other basket into the Quantum's before dropping in the assembly. Made sure the pump was consistently quiet (full?) before taking it for a spin.

On your step 9 bit, simply cycling accessories should do that since excess pressure gets cycled back to the pump assembly at the fuel filter.

Transmission will be replaced in a month at most. Timing and what not. So will have to wait until then for more testing.
Have you gone full throttle a number of times with yours yet? Or have you not floored?

Yeah, I too did the cycling the key a number of times waiting for it to quiet for each of the two pumps prior to starting for the first time. I did the Adaptation for each as well. I even drove mine on light throttle a number of times before actually flooring it. Again, under normal driving it was fine including the data pressures...until flooring it, placing it under load, and increasing the duty cycle of the pump. Perhaps it was something altogether different with mine. But I know how air in a pump can affect pump volume...as I've seen it with Koi pond pumps. I believe step 9 is precautionary as it may or may not happen with each pump...but we found nothing else and it fixed itself. Step 9 was all I saw I didn't do...no idea what else it could've been.
 
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ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
I apologize, because all this time one thing had slipped my mind.

How do you feel about removing and checking your N80 EVAP purge valve? Or simply replace it.

The failed or plugged N80 can cause lean and increase trims, and a rough idle or even hard starts when tank is near full or topped off.

To test it; Just remove it and apply vacuum(if you have Mityvac or something similar) to the intake manifold side to see if it holds with vacuum applied. You can test if the solenoid operates electrically. But this is likely not the case because a code would typically be present if it fails electrically. My guess is it is filthy inside and no longer seals shut.
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
Not worth the risk to floor it. I'll push 10psi tops, but that's it. And nothing interesting until 3rd gear. If it hangs on to 2nd too long it locks me out of the gearbox and puts the car into 1st. Can't shift until I pull over and cylcle the ignition. New gearbox is at the shop. Just have to coordinate install.

I have a replacement N80 valve (the little guy at the front of the engine bay, right?). Did everything on my list above except for:
  • N80 valve
  • Rear breather tube hose clamps. I replaced these, but don't think I have a good seal. Thing is a pita to pull off the valve cover. Should I be able to move the breather tube straight back once out of the hose? If not, then I might have broken it 😬
Cleared codes and went for a short drive after doing everything else a few days ago and my LTFT partial is now +8.2, but idle is +2.81. STFT spiked to +23% - +27% once the sensor kicked in after a clearing codes and a cold start.

Did notice what I suspect is oil build up around coil pack on cylinder 3. Cleaned it off and will check it again in a few days. Weird because the cover/gasket were serviced last year. No more leaks from the oil cap area.
 
Last edited:

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Not worth the risk to floor it. I'll push 10psi tops, but that's it. And nothing interesting until 3rd gear. If it hangs on to 2nd too long it locks me out of the gearbox and puts the car into 1st. Can't shift until I pull over and cylcle the ignition. New gearbox is at the shop. Just have to coordinate install.

I have a replacement N80 valve (the little guy at the front of the engine bay, right? YES). Did everything on my list above except for:
  • N80 valve
  • Rear breather tube hose clamps. I replaced these, but don't think I have a good seal. Thing is a pita to pull off the valve cover. Should I be able to move the breather tube straight back once out of the hose? NO, the tube isn't flexible. If not, then I might have broken it 😬 Oooo, maybe.
Cleared codes and went for a short drive after doing everything else a few days ago and my LTFT partial is now +8.2, but idle is +2.81. STFT spiked to +23% - +27% once the sensor kicked in after a clearing codes and a cold start.

Did notice what I suspect is oil build up around coil pack on cylinder 3. Cleaned it off and will check it again in a few days. Weird because the cover/gasket were serviced last year. New cover? Or just the seal for the cover? Did the new cover, if it was replaced, have new bolts? The bolt's seals, if old, may be cracked or hardened and no longer sealing. No more leaks from the oil cap area.
What type clamps are you adding to the connector hose for the cover to tube? Are you replacing anything...the short hose or breather tube?
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
Replacing the one time hose clamps on either end of the black rubber hose. Was originally just getting rid of the zip tie on one end, but I removed the other clamp to work everything free. The new OE clamps I have were so tight I couldn't get the black hose back on the valve cover with the clamp mounted on the hose. So, used a wormgear clamp I had and one new crimp clamp which barely crimped on that end.

May have damaged the breather tube too (bent it toward the firewall to get it out of the way), but I'm gonna redo the clamps beforehand. It all fits together as it did. Just don't think it's tight.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
OK, so if you are using worm gear clamps because they come apart and, because I am not familiar with your skill level...the hose doesn't need to be disconnected so long as you can remove the existing OE style single ear clamps. The OE single ear clamps can be taken apart without sliding the hose off. You can cut them at the ear with a cutting disc and Dremel type tool or if you can access this tab, bend it straight (with whatever pliers that will grip it best) so it can slide out of the slot (a small flat driver may be needed to loosen it) and you can take the clamp apart. But it seems the metal tube needs some inspection and may need to be removed;
clamp.png
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
Right, that's why worm gear clamps are easier. No removal required to get them on. I had no problem getting the single ear clamp off when I took it all apart. The breather tube did not want to budge when trying to remove it from the black hose (which is where the zip tie was). Wasn't originally planning to remove the black hose entirely, but removing it all from the valve cover, then pulling the hose off the breather tube was easier for me...
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
I will add that the breather tube I have has what I'm guessing is a check valve in it that was essentially moving freely about, but couldn't be moved down the tube itself. It looks like this. To my knowledge it has never been updated/replaced.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Right...it is a check valve. It allows flow to the turbo inlet when crankcase is under pressure but seals when in vacuum so intake air cannot bypass the turbo.
 
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