Sam's build thread

[sambb]

Alright I need help with VCDS and LTFT's and STFT's. Seb helped me out today with a 4 bar fuel pressure regulator. There's a lot of tutorials out there that tell you how to observe your LTFT's (long term fuel trims) in VCDS and then change either ch 8 or ch10 in unisettings to either add or subtract fuel and offset the compensations.
I installed the 4 bar FPR tonight. Its usual that you first go for an extended drive with some conservative pulls, see what your partial LTFT's are doing and then start by adjusting ch10 for multiplicative fuelling. After that you play with ch8 if need be to get your gentle progression/cruise/idle dialled in. I wanted first to just have a look at what was happening at idle and see how the trims had changed with the higher fuel pressure and then how they'd transfer over and become LTFT's. I was surprised to see that not only were the idle LTFT's solid but the idle STFT's hadn't changed at all - they were both stuck on 0%. Its my understanding that you should see the STFT at idle oscillate as the o2 sensor oscillates but this wasn't happening either. To really test the STFT's I then added a vacuum leak to the car - pulled the dipstick, pulled the boost gauge vacuum hose and finally popped the cam cover cap. None of these, which should 100% induce a lean condition causing the STFT's to start adding fuel immediately, registered at all.
I then thought the o2 sensor must be dead but its voltages and real time lambda are varying in block 031. At idle the specified lambda was of course 1.00 but it was sitting at 0.84 which is what you'd expect from more fuel pressure. I then went ahead and made decent adjustments to ch8 for additive fuelling which affects idle and I could see that the unisettings ch8 changes I'd made were showing as either richer or leaner o2 sensor voltages/lambda depending on what I was doing with the channel. I never moved it far enough to get it to lambda 1.00 though as that's not the normal time you would do this.

So why is the o2 sensor seeing changes (seemingly working in real time) but does not seem to be inputting to the fuel compensation blocks in 032 and 033??
I could go ahead and do my loaded runs and log active lambda and go back and forth until I get the injectors and mixtures dialled in for the new fuel pump/FPR, but it'd be so much easier if I had the compensation values to run off. So whyTF are they not working???

need help tuner/vcds people please.

[sambb]

ok I think my o2 sensor is dead. In block 033 the lambda % stays on 0% (it should fluctuate), however the voltage does fluctuate slightly. Also in block 030 my values are 010 and 110. This means it is heating on and off ok, is always ready, but the third digit should show a 1 for control being active. I never get that 1 so its not doing its thing. I have a spare under the house from the old car but really .... every time before an event there is a drama. I'll be lucky to get out of this one in time though.

[metalhead]

Dumb question, but was the car up to temp, and does it use the o2 sensor when cold? My aftermarket fuel injection only switches over to using the o2 sensor when the engine is up to temperature - that's why you may have noticed my car tends to be grumpy when starting and idling around the grid, it runs very rich when cold and I haven't got around to leaning out those areas of the map, it runs heaps better after a run.

[sambb]

ha ha yeah that was my annoyed falling asleep last thought last night too. Today I did kid drop off which got it up to temp and then brought it home and plugged it in and still no joy. In VCDS there are lots of ways to look at the 02 sensor. Its weird because you can see the real time lambda change when you give it a rev (although its idling at 0.85 when specified is 1.00), but the lambda %, and o2 voltages are fixed and the short term trims still weren't changing if I introduced an air leak and the long term trims hadn't moved from 0% despite driving around with an extra 1 bar of fuel pressure. The 3 digit readiness number still had a zero where there should be a 1 to indicate that the o2 sensor is active. Letting it cool down now and then i'll get under it and change the sensor out for my spare if I can find it that is.

[metalhead]

I've got a spare, pretty sure my sensor is a VW one, so might be the same! I'm not terribly local to you though.

[sambb]

super confused. Put in my working spare that had been on the old car and exactly the same story. In 001 and 030 and 031 its behaving the same. I'm thinking I'll maybe have to test the circuit from the o2 sensors J box back to the ECU. The other thing it could be is that I'm misinterpretting whats happening with those previos blocks I just mentioned and its just that my cracked version of VCDS doesn't support looking at the STFT and LTFT blocks, but I doubt it. Thing is though, I've been playing with lemmiwinks fuelling channels and the mixtures do change and are seen as such with the sensor. ???

[sambb]

**** yeah!!!! Danny_ric is an executioner. Turd day. The lead up to this sundays Canberra hillclimb round was a debacle really. The car still wont go into closed loop so I had no fuel trims to use as a guide to tune the fuelling with the 4 bar FPR using Lemmiwinks. It all had to be by repeatedly logging the real time values which can get very illegal so It was hard to be methodical about that. The 4 bar worked a treat in the mid range/top end and I was able to get 0.83's into it with a much more acceptable 80% duty cycle, when in comparison the 3 bar had the injectors at 96% in spots at WOT. The idle/partial/progression side of things is way overfuelled though and I cant get it better yet than .83-0.91 driving around town which is too rich. I ran out of time and was actually still logging it on the freeway on the way to the race this morning when the ESP light came on which is a dead give away of the MAF. So the MAF sensor died whilst on the freeway half way down to the Canberra and not a spare sensor in sight. Reseated sensor and ECU plugs, cleaned the terminals, full battery off reset of the ECU, metered the wiring etc and dead sensor. Wasn't going to go ringing its neck on the track when the MAF is out of the equation and the fuelling is a bit up in the air anyway so I made the head over heart decision to do a sad U-turn and drove home. I'd swapped in my spare sensor whilst chasing the closed loop problem I've had a week earlier. Its been faultless but then waits till I'm nearly at the track to die. Felt like a water logged ball all day especially because my times from September on the old suspension would have put me in second and the car is Waaayyy quicker now. But then Ricciardo went and slayed them in the F1 so all is good again. Hopefully Andrew jumps on with a report. Getting a really good result in the championship as a whole is a non goer now, so now the aim for the year has basically changed to try to get my first class win and to cracking Eddy's wakefield time (if I ever get the engine running sweet again that is!). Don't know what it is about April and owning a Polo - It was this time last year that an SUV ended the old Polos life and now this happens. Maybe i'll just rent a car this time next year!

Plenty to do now though. Short term need to find out why it wont go into closed loop and then get it running properly on the 4 Bar. Need to fit my longer 200mm front springs so I can finish off the front suspension. My auxillary turbo/water pump is on its last legs and needs to be replaced (wary of parts off the old car now). Still need to helicoil the water banjo bolt on the turbo CHRA to make that reliable.
Long term will track down some bigger injectors and go back to 3 bar FPR and get the K03s tuned as well as I can with left foot brake, linear throttle and maybe a two step. I'm determined to get a class win or crack the Wakefield time but want to do it the hard way with a K03s. It'll be all the more sweeter if I can do that and I may just stay married by not taking on more big stuff this year too. If I can achieve either of those then I'll sell all the K03s stuff/tune as a kit and move onto something a bit more Garretty maybe.

[simon k]

balls... shit day.... I must've been getting the shit vibes from you because I woke up feeling like crap and spent the whole day like it

but sounds like you're all over it

[sambb]

yep all fluffy now. Have a good lead on why the car might not be going into closed loop which i'll check out. Main thing is now I know why the turbo was feeling a bit flat. With it fuelled properly its a weapon again so that's why I'm happy to hang onto the K03s. The only reason why the old car must have gone like a trooper with the same turbo seems to have been the water injection. I don't think I ever really gave the water the credit it deserved. By itself it must have been equally under fuelled so its amazing really how on song it was with a pretty rudimentary single nozzle system.

[simon k]

I had water on my mini - I reckon it's the kind of thing that you don't notice when it's there but you really notice when it's not... I had it to cool the blower & intake, but it would've made a performance difference too

my nutjob mate Jason hooked up the windscreen washer to the intake of his automatic civic, he reckons it worked well, but then it locked up the front wheels, and kinda stopped running properly, and pumped all of it's water out... hydraulic locked & lifted the head...

[sambb]

I may do it again. E85 is tempting but I drive the car all over the state and it might not be practical that way. So it'll be 98 ron + water if I ever want to push things. Doing it again it'd either be pre comp boost pressurised (if I'm still running an undersize turbo) or direct port. For a car that still had the side mount and only had a dump pipe 190g/s (240hp flow crank based on the maf flow) was pretty solid. Pure water too, no meth as srutineers dont like that in a road reg car.

[Sydneykid]

I've been running cars on E85 for over 10 years and yes trips do require a bit of planning in advance. There is also the 25% or so reduced range on a tank to consider. These days we pretty much only use United E85 and their find a store app comes in very useful.

Find A Store | United Petroleum – 100% Australian Owned

Before you make the call to go to E85 I'd strongly suggest looking at where you travel to and then see if there are outlets on the way. For example on my way to Bathurst there are 9 servos with E85.


Cheers
Gary

[metalhead]

Coming in late here. Sucks you had such bad luck. While Canberra is a great little track (I'd never been there before), the weather was horrible, and no one was near their normal times. I don't think it reached 14C all day, and there was an icy wind as well. I don't normally feel the cold, and I was wearing a jacket with hood over my driving attire and feeling frozen.

I was happy with how I drove, considering I'd never been there before, and was running new tyres and brakes for the first time, so the car was quite different. Unfortunately I seem to have cracked a header, and after the first two runs the car was way down on power and fluffing badly, as the o2 sensor was reading lean and pumping way too much fuel in (kinda the opposite of your problem Sam!).

[simon k]

Unfortunately I seem to have cracked a header, and after the first two runs the car was way down on power and fluffing badly, as the o2 sensor was reading lean and pumping way too much fuel in (kinda the opposite of your problem Sam!).

Sam should've kept going... you could have made 1 good car out of the two

[sambb]

Yeah I should've at least had breaky there and watched the first runs.

I sorted out why the car wouldnt go into closed loop. I knew the N249 delete could affect fuelling if its solenoid wasn't resistered properly. What I didn't know was that the same is true for the SAI delete. Id thought that If you had the SAI delete as part of your tune that there was no need to resistor the solenoid so I'd left it unplugged/ open circuit. Well doing that means that the o2 sensor for some reason never gets full readiness as seen in VCDS block 030 - you need the last digit to be a '1'. O2 sensor mixtures will appear ok in block 031 which is commonly logged for power runs (which made me think everything was ok), but these values become just read only and do not update fuel trims because you are permanently in open loop. So if you've deleted the N249 and SAI then check that you've resistered BOTH or youll be locked in open loop. One the resistor went in, short term fuel trims started changing immediately and once the car hit about 70 or so degrees the long term fuel trims started compensating for the extra fuelling.
I'm just waiting on some 380cc injectors before a proper 3 bar tune for the K03s gets done, but now at least in the mean time I can use uni settings/lemmiwinks to tweak the fuelling for the 4 bar FPR now that I'll have long term fuel trims to work off.