GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

High LTFT K04 BPY

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
I'm going to pick up a used MKV basket on eBay. They cost less than half the Quantum pump and all I need is the basket/sending unit. And no sweat, dude. Knew what I was signing up for when I bought the Quantum. It'll let me install the Quantum pump into the FSI basket without taking the car down though. Should've kept my old pump. 🙃

The controller was replaced late last year and provided a significant improvement. It is the latest revision (1K0906093J). I think I had rev. C? Super old. They don't even look the same. Latest revision has a metal backing with tiny heat sinks in it.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
OK, getting the proper basket sounds good.

I believe you may want to ask Torqbyte about the revision of the controller if you ever think you might add the PM4. They told me when I replaced my controller that the revisions after the G didn't seem to play nice with the PM3. I had ordered a controller just before I talked with them and what I received was the H and it was made in China(also had a metal plate). My dealership just kept it and ordered the G for me. The VW parts guy told me there were just two Grevisions left in the country at VW warehouses and I ordered both and have a spare now. Wait, never mind. I just remembered the PM4 eliminates the controller. :censored:
 
Last edited:

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
So I got the pump, however, the plastic tube connected to the top of the basket assembly is no longer properly attached. Looks like this is the fuel return line. It stays in place if I press up into the spot, but I can remove it without too much effort. Think I can JB weld it and move on? Picture for reference.

IMG_20200429_103250.jpg
IMG_20200429_105115.jpg
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
:rolleyes:
That ain't good.
I believe JB or Seal-All would be good choices. You could try Loctite Plastics-2 part.
Just note if your choice works on polyethylene or polypropylene plastics. The hardest plastics to bond.
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
Cool. Will do. Quantum pump is in the basket already. The OE hose was a pita to get off the top of the assembly, but I eventually got it. It's in two pieces now until I can re-attach the drain tube. Close!
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
Well, according to data sheets for JB Weld and Seal All, neither works well on polyethylene (PE) or polypropylene (PP).

JB Weld: https://www.jbweld.com/faqs
Seal All: http://eclecticproducts.com/downloads/tds-seal-all-english.pdf

Whatever was used at the factory wasn't something that melted/bonded the plastics together. It looks to be a simple adhesive. Since it's the return line, the fuel coming out of it won't be under a lot of pressure, correct?

Edit...
Loctite Super Glue Plastics works on PP and PE though: https://www.amazon.com/gp/product/B000Y3LHXW
 
Last edited:

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Right, should just be feed back from the filter regulation. Because there is no return from the rail. The rail only reroutes back into the low hpfp feed line. At most, it will be; dribbles to a 95 psi stream.

And right, so I meant JB or Seal-All should work...'or' find one that works on PP and PE because if you find one that works on those, it should work well on all plastics. I used Gorilla glue on the power post where my laptop's power cord plugs in. It's held for 9 years, but it isn't fuel resistant. If it were, I would've suggested it, LOL. I thought for sure it would fall off within a week.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
OEM tube a pain...I scored it longitudinally at the ends with a blade and then it broke through when I applied a bit of pressure by installing a small driver tip inside the end of the tubing...between the inner tubing and the outer surface of the port. It just popped off.
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
The pump is in and working. My trims haven't changed much since driving around today, but down to +18.35 long term and short term mostly at +1.21. In the car, less is more once you're in boost. The pump sits at 4.5 bar even at idle. It's also very quiet.

Downside? The sending unit isn't working for some reason. I'll pull it out in a week or so to see if I can fix it.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Sender probably wasn't working before you got it. A sender is near as much as an aftermarket pump w/sender.

I too noticed it wasn't noisy.

I wish I had some more running time so I had more data to share. My LTFT off idle was 5.x%, down from 7% to 8% before the injectors were replaced, when I saw the data after my pump failed the other day. The drop is likely due to the new injectors...maybe the pump if when running well it had an effect. I imagine the off-idle additive will drop again given the pump wasn't providing proper pressure and the rail pressure was dropping.
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
Sender probably wasn't working before you got it. A sender is near as much as an aftermarket pump w/sender.

I too noticed it wasn't noisy.

I wish I had some more running time so I had more data to share. My LTFT off idle was 5.x%, down from 7% to 8% before the injectors were replaced, when I saw the data after my pump failed the other day. The drop is likely due to the new injectors...maybe the pump if when running well it had an effect. I imagine the off-idle additive will drop again given the pump wasn't providing proper pressure and the rail pressure was dropping.
Regarding the sender, possibly. I did have to rotate the pump almost 180* when installing it and I felt some resistance from the float so it may just be stuck.

If trims don't drop, then I'm going to replace the hose clamps at the rear breather tube as one of them is a zip tie right now. I have a PCV delete/block off and don't know if the rear breather has a check valve in it or not. Aside from that, my only other thought is O2 sensor. Have already replaced the MAF and there aren't any other leaks before the turbo unless my DV is leaking (dump tube).
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
These are some common causes for it running lean, as you know;
  • Unmetered air leaks, torn intake boot, leaking intake manifold or gaskets&seals
  • Crankcase vent system fault, system valve stuck open
  • Low fuel pressure, pressure regulator malfunction
  • MAF malfunction, sending incorrect signal information
Unmetered Leaks, but there's more; includes metered air leaks. It can be leaks post/after turbo...up to and including the intake manifold.
Crankcase function; sort the possibilities of leaks which you plan to do.
Fuel pressure; can be fouled/dirty injectors. Failed (low pressure)regulator in the filter or failed high pressure regulator in the hpfp. Fuel data should sort the pressures. The difficult test with VCDS is pressure bleed off because each time we use VCDS, the ignition is turned to run and the pump primes. This is one way to check for bleed off but not many have this set up. Also, it is for checking difficulties when starting, but the concept is ideal for checking drops in fuel pressures in both the high and low sides of the fuel system;
MAF; you've already dealt with.
 

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
These are some common causes for it running lean, as you know;
  • Unmetered air leaks, torn intake boot, leaking intake manifold or gaskets&seals
  • Crankcase vent system fault, system valve stuck open
  • Low fuel pressure, pressure regulator malfunction
  • MAF malfunction, sending incorrect signal information
Unmetered Leaks, but there's more; includes metered air leaks. It can be leaks post/after turbo...up to and including the intake manifold. If under boost, wouldn't a leak post turbo cause the engine to run rich? Or not be able to meet requested boost levels? I've checked all connections from the air filter to the throttle body. Valves were cleaned in February and a new manifold gasket was installed at the same time.
Crankcase function; sort the possibilities of leaks which you plan to do. Where else besides the front PCV and rear breather should I check? I'm holding just under 20 Hg at idle.
Fuel pressure; can be fouled/dirty injectors. Failed (low pressure)regulator in the filter or failed high pressure regulator in the hpfp. Fuel data should sort the pressures. The difficult test with VCDS is pressure bleed off because each time we use VCDS, the ignition is turned to run and the pump primes. This is one way to check for bleed off but not many have this set up. Also, it is for checking difficulties when starting, but the concept is ideal for checking drops in fuel pressures in both the high and low sides of the fuel system; Brand new injectors installed back in February. New fuel filter last year. Running latest rail sensor (red/orange) which was installed last year. Pressure sensor on the APR HPFP was replaced when it was installed maybe 2-3 years ago. When the LPFP primed this morning before turning over the engine, pressure reached 4.8 bar.
MAF; you've already dealt with. Yep.
Some comments above in red.

If I understand the workings of STFT and LTFT correctly, STFT should go rich once my lean condition is fixed which will, in turn, cause the LTFT to self-correct to a new value. STFT will then steady out either slightly rich or lean once the new LTFT baseline is reached.

...and, if everything else above checks out would you consider the front O2 sensor as a potential culprit? I was about to purchase the front and rear before I found the LPFP pressure issue through logging. Not so sure what else I would look for unless the HPFP has bad seals and, therefore, it's losing fuel as it pumps. It would create a similar condition which the computer would try to correct by adding more fuel. I have a brand new APR pump I could install... :unsure:
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Some comments above in red.

If I understand the workings of STFT and LTFT correctly, STFT should go rich once my lean condition is fixed which will, in turn, cause the LTFT to self-correct to a new value. STFT will then steady out either slightly rich or lean once the new LTFT baseline is reached.

...and, if everything else above checks out would you consider the front O2 sensor as a potential culprit? I was about to purchase the front and rear before I found the LPFP pressure issue through logging. Not so sure what else I would look for unless the HPFP has bad seals and, therefore, it's losing fuel as it pumps. It would create a similar condition which the computer would try to correct by adding more fuel. I have a brand new APR pump I could install... :unsure:
Post turbo leak question; When in boost yes/maybe. I know, I'll explain in a bit.
The additive in the multiplicative block #2 is for delivery of fuel when off idle driving or "throttle plate Open"...doesn't mean when in boost. It's the average ffrom when the throttle plate is open and we all drive sub boost most of the time. Regarding post turbo leaks(the explanation I mentioned); If it were leaking post turbo, and this were the only problem, the MAP should correct the low MAF report off idle and the LTFT off idle should not rise..this is correct. Unless the MAP is not reporting correctly. This is why you confirm no leaks. Because then if leaking, you fix the leak and replace the MAP.

You've checked the at idle trims right after doing a "Clear Codes" right? You do not see a big jump immediately after a "Clear Codes" and then see it adjust to near 0 do you? I believe you mentioned you checked that. If not, then the high addition off idle is going to; not likely the fuel delivery because of the recent swaps, not likely to be the PCV; explain in a moment, but more likely the O2's or EVAP system leaks or valve is functioning incorrectly. And yes, the PCV function is the two PCV bits. I believe the PCV can still be the issue because of the PCV delete. So is it the PCV or EVAP? The PCV and EVAP are two that allow un-metered air back into the turbo inlet. If too much is reintroduced, then the calibration to allow for this will be off. So, you can just replace the O2's, suspect the EVAP system, or try going back to the oem PCV.

Both O2's can be the fault for high off idle trims. The rear O2 reporting too low a reading can cause I high off idle addition. I believe having the angled O2 spacer for the second O2 on mine is responsible for the 5% to 8% I have seen on mine over the past number of years. I have gone through it and smoke tested and found just one leak and went back to the oem PCV. I mentioned I did have near 17% once, but fixing a leak at the MAF to intake seal dropped it then to 8%. Now doing the injectors and fuel pump it is nearer 5%.

I've been going on so long I may have made mistakes...let me know if you see any or question any of it, LOL.
 
Last edited:

BurgerGuy

Go Kart Champion
Location
Charlotte
Car(s)
'07 K04 GTI
I have a new MAP sensor that I haven't taken the time to install yet so I can rule that out in the next few days.

I did not clear codes to reset trims. Wanted to see how the STFT would respond to the upgraded pump so I left everything alone. LTFT went from +19.75 to +18.35 after a day of driving and hasn't really moved since. With the EVAP system, is it the hoses or the purge valve itself that go bad? Need to check the o-ring on my gas cap too. This may be the next system to check as the LTFT has a tendency to fluctuate between +14 and +19 sometimes and thinking back it may be lining up with when I refuel (screwing down the gas cap). Some time earlier this year I got a code for "very small leak detected" in the EVAP system, but it hasn't showed up for quite a while.

With the PCV delete/block off, it just means all the crankcase vapors are flowing through the rear breather which means more oil and crap through the turbo and charge pipes. Not sure if the gasket for the front PCV is leaking so will check that too. I guess easy way to tell would be if there's oil build up around the block off plate itself, right? Valve cover could be messed up as well like yours was. Catch can would be the best solution, but I'd rather put that cash towards the transmission.

The logs seem to indicate both O2 sensors are playing nice with each other and based on fuel data the lambda values seem to line up, but perhaps I missed something.
 
Top