New to the forum with few probs.

[Rosso TT]

Hi, my name's Ross, i live in aus and i'm a proud owner of a tt quattro.
You might wonder why i'm posting here instead of the tt section or the ttoc( i'm a member there too)
but i've been following this for quite a while and i found out there are some very knowledgeable members on here regarding 1.8T.
So, here's my dilemmas
How do i post screenshot of my logs? I have microsoft works spreadsheet.
I've been playing around with my fuel system for about 2 months, i fitted a pressure gauge near the injector rail and i can see about 3.5 bar at idle ( got 4 bar fpr) and goes up to 4.2 bat just before the turbo starts spooling up, after that the pressure drops to 3 bar at 6000 rpm.Is that normal?
I replaced the fuel filter couple months ago, today i replaced my fuel pump and neither of them had cured the problem if that's a problem at all.
I thought i should see no less that 5.4 bar of fuel pressure but the guy that sold me the pump told me that intank pump don't do over 4 bar.
I'm comfused.
Thanks.

 

[cecilthesausage]

For a start you don't need a 4Bar FPR... The standard 3 Bar one is more than sufficient...

 

[Rosso TT]

Cheers cecil, i thought about that, it will be my next move.

 

[<tuffty/>]

Sounds like the pump is on its way out or the FPR is blocked... as stated there is no reason at all for a 4bar FPR... fuel pressure on boost should be FPR rating + actual boost so at 1.2bar boost you should see 5.2 bar fuel pressure...

First thing to do is stick a 3bar FPR back in then start logging using VCDS to see what the fuelling is doing... if the fuel pressure is dropping off that much at high RPM/boost I would expect to see big differences between fuel request and fuel actual on block 31 assuming yours is a wideband ECU else get it on a dyno and check with an AFR probe...

You would be advised to not rag your car until you have diagnosed this problem as going lean is a very bad thing...

<tuffty/>

 

[Rosso TT]

Thanks tuffty for your reply, my engine code is an APX so a narrow band can't even access block 112 egt, but i found another block 217 and strangelly enough i can see egt plus some lambda signals.
Next on the list is 3 bar fpr, one more fuel filter change, blowing the fuel lines with compressed air, check fuse, relay and harness to fuel pump.
Also yesterday i ran the car with a new intank pump but hasn't got the 2 feeding lines for siphoning fuel from one side of the tank to the other so i connected the return line to the siphon system and i've got 4.2 bar of constant pressure but still dropping at 3.2 bar at 6000 rpm.
More food for thought.

 

[Rosso TT]

Ok chaps, done some more tests today.
Here's what i've done: replaced fuel filter, blasted clean with compressed air fuel line and cheked for kincks, inpected injectors,fitted 3 bar fpr, pressure tested fuel pump assembly in a backet full of petrol and connected straight to the fuel rail, applied 1.5 bar of pressure to the fpr and could see 4 bar of fuel pressure, hard wired the pump directly to the battery.
Done all this with no success, fuel pressure still dropping when on boost.
Unless injectors go to 100% duty cycle at 3500 rpm, it's like someone opens a tap.
Next on the list is: in line fuel pump, new set of injectors, external fuel line.
Anyone had similar problem or have any suggestions?
P.S do not pour petrol on headlight lenses they will crack. Ouch.

 

[Rosso TT]

Ok, fitted my new oem fuel pump yesterday and today i went for a test drive and logs.
Now the fuel pressure follow pretty much the boost pressure pattern and on idling with hose off the fpr i get 3.3 bar of fuel pressure, more than is should.
So i did some logs and what do you know?
It didn't fix the problem, still getting 6 and 7 cf, flow is 170 g/s at 6000 rpm, requested and actual boost are the same, though it peaks at 2300 mbar, iat is no less than 13c and no more than 25c above outside temp and trims are -0.7 and -4.7.
I think my revo settings are boost 6 and timing 2 but since then the battery had been disconnected and remembering with these settings the car would run 210 g/s of flow and no more than 4 cf.
Then it sprung onto my mind what Bill had said about oil fumes retarding cf, so i decided to make a catch can out of an energy drink bottle, went for a log and i could get slightly better results as 190 g/s and 6 cf, I'll run the car like this and i'll take some more logs next weekend.
Also did a lil video of my blow by have a look, hose under inlet mani is disconnected and plugged.
http://www.youtube.com/watch?v=tueCtRSSDJQ

 

[badger5]

thats a fair amount of crankcase pressure there...

I would do a compression test and leakdown next.. see whats occuring..

 

[Rosso TT]

Thanks Bill for your suggestion, will do.

 

[Rosso TT]

OK, done comp test and leakdown test today as suggested by Bill.
Comp test, starting from cylinder near FW 169, 166, 167, 175 psi, engine about 60 C temp.
Leak down test, found leak at the end of top charge pipe and to the DV connection to the TIP.
Also i disconnected the PCV system, bung the TIP and i could still see smoke coming out of the oil filler cap and if i put my hear near it i can hear a ticking sound coming inside the engine and goes away as soon i release the pressure.

 

[Rosso TT]

Does anyone know wich is the channel on unisetting for enriching fuel mixture as my tuner said that with REVO he can't adjust it on its own?
Car is running about 12* BTDC of timing on WOT and i don't want to pull it back further.

 

[s3dave]

Does anyone know wich is the channel on unisetting for enriching fuel mixture as my tuner said that with REVO he can't adjust it on its own?
Car is running about 12* BTDC of timing on WOT and i don't want to pull it back further.

channel 10..

 

[badger5]

Does anyone know wich is the channel on unisetting for enriching fuel mixture as my tuner said that with REVO he can't adjust it on its own?
Car is running about 12* BTDC of timing on WOT and i don't want to pull it back further.

You should clear adaptions (faultcode reset) and see what block 001 does on cruise/idle and wot (if wideband car)
If non wideband the adjustments should stick, but beware over time they will adapt, so keep an eye on 032 block and see what its pulled or added... as you may find you add 5% and find 032 is sat at -5%, aka nett nothing

Wideband cars in my experience under boost dont react to adjusting fuel terms.. they run closed loop fueling, end of.

 

[Rosso TT]

Thanks Dave and Bill, my engine is APX so narrow band.
I'll have a play this weekend hopefully.
From that i gather reading mainly this forum, an healthy 1.8T with stock k04 should see 220/225 g/s and 12*/16* ing timing, that's wat i'm trying to achieve and enjoy it for a while.

 

[Rosso TT]

Had the opportunity to stick my car on the dyno to check AFR mainly and got around 12.3, so i won't be playing with unisetting just yet and got 245 BHP, wich is pretty much what i'm getting as air flow, so i'm about 35 horses short.
Also done another smoke test from the tail pipes and found out that i had a leak on my down pipe flange to the turbo.

 

[Rosso TT]

Done few more logs today and also logged with the n75 disconnected.
Found out boost goes up to 6 psi up until 4500 rpm and then starts rising up to about 15 psi at 6000 rpm.
Is that normal?

 

[<tuffty/>]

Done few more logs today and also logged with the n75 disconnected.
Found out boost goes up to 6 psi up until 4500 rpm and then starts rising up to about 15 psi at 6000 rpm.
Is that normal?

Boost creep... have seen this alot on K04's... std and hybrid for that matter..

<tuffty/>

 

[Rosso TT]

Thanks tuffty, so, what would be the solution?
New actuator or as my mate mechanic said "just stick a bigger turbocharger in there, that would solve all your problems"

 

[badger5]

actuator will not fix creep.. The ports inability to flow is why it creeps. Porting it bigger cures it

 

[Rosso TT]

Thanks Bill for the reply, i guess i won't be tacking the ko4 off any time soon, though, i would like to porting it myself, that's what i use to do back in Italy on 2 stroke engines, i still got steady hands.

One more question.
I was listening at the fuel pump priming on one of my mate's TT and i believe mine only primes for a second or less whilst my mate's does last 2 seconds.
If i replace the pump relay would that fix it or need to replace something else?
Thanks
Ross

 

[badger5]

I am not sure what sets the prime time.. not sure if timer in relay or ecu drives it on-off

 

[Rosso TT]

Thanks Bill.
I'll try and find out myself, i might get a new relay, they're not that expencive.