interpreting measuring block 000 in vagcom and AAN vacuum leaks

[ottawa coupe]

so, one of the things i had on my back burner that I thought I had prepared for was the speed density ecu conversion and TTE420 install on my S6. i thought the car was in great shape and ready to go. not so.

i swapped ECU and injectors into an otherwise stock engine to ensure that i didn't kill the ECU with the soldering iron. i was just going to idle it and confirm life, then the turbo would be changed.

well, it barely ran, belched smoke and was just this side of flooding. so i guess i didn't have the right foundation yet! queue much investigating, well not much. it was clearly a vacuum issue as a speed density lives and dies on vaccuum.

i put it back to stock and got a guage on it and it was only drawing 7in HG (dunno what that converts to in real units). apparently the target should be somewhere around 18-20. after a bit of poking, i found a loose hose and a small tear in the turbo inlet boot. tightened the hose and hopefully sealed the tear (no sense in replacing as the new turbo uses a different size boot). i got it to 16/17.

now, in conjunction with this is the handy measuring group 000 in vagcom. it has 10 blocks of information which point you in the right direction for faults. i should note that there are zero fault codes and haven't had any throughout this process, which is why i thought i had a solid base i guess... at any rate, of the 10 blocks, 9 are now within spec. the 2nd one suggests i have an air leak between turbo and throttle. i have smoke tested the daylights out of everything and have not seen any smoke anywhere, even with the 2 issues noted above. my last thought about it is the idle circuit. is that considered between turbo and throttle? i have tee'd into that between isv and manifold for my vacuum booster. this could be causing the issue couldn't it...

i note that when i only slightly crack the throttle, vaccuum goes to ~22in... seems to me there's something going on with that branch of things?

that seem a logical interpretation to you guys?

one thing that has not been measured yet as i am waiting for the gauge to arrive is fuel pressure. i have a walbro 450 pump in it, it is possible it overwhelms the FPR's ability to regulate the pressure. to be determined at the earliest opportunity

[tekstil]

i swapped ECU and injectors into an otherwise stock engine to ensure that i didn't kill the ECU with the soldering iron.

What kind of injectors you swapped in? Just bigger ones? Did you make software changes to ECU aswell, telling it injectors size in cc and deadtimes? If you didn't make any changes, then the result (flooding) is to be expected. This is assuming you're talking about converting stock ECU to speed density.

[ottawa coupe]

It's the full speed density/tte420 package i am putting in. Did the ecu conversion myself as i didn't want to risk potential shenanigans shipping/importing north and south. I was testing that ecu with the injectors only just to ensure i didn't break the ecu. I've been swapping ecus/injectors as required to troubleshoot

my car is a relatively low miles one and i had assumed all was well mechanically (and it is) but the 30yo rubber lines are getting more fragile than i had thought. Vacuum/boost leaks galore. Which is not a good thing on a speed density setup lol. Oodles of money spent on bits at tradition to get it all sorted properly again.

I am getting to the bottom of the situation now and will get a datalog from vcds to the tuner asap so he can revise things.