DocWyte

So in the course of trying to figure out why my car isn't seeing the boost that it should and runs like crap at WOT I discover that the throttle body isn't seeing WOT as such. Even after I do an adaptation with the VAG it only reads idle and part throttle.

Thanks to Larry Sr. I install another t-body. Much to my distress it does the same damn thing! I've tried multiple chips, including the stock one and multiple ecus to no avail.

WTF?! Need some help here guys, throw me a bone!

Donkihad

I remember reading on the forum somewhere, that you never get a reading of "full" throttle...NonDBW?

DocWyte

You never see a reading of 100% on the VAG, but you *are* supposed to be able to read full throttle. For the throttle cable cars the 3 settings you can read are idle, part throttle and full throttle...

SMOKINA4TURBO

you can file down the stop so the throttle body will open up more under WOT. On Dan Harmans car they measured it from 85.5 degrees to 91.7 degrees. I'm not sure if this is the right thing to do though. MC aka Clark aka Turbo5 did it and so did his counterpart Dan.

zain

(Applicable to pre-DBW cars here) when the throttle plate is wide open, then VAG reports throttle at no more than about 84%. This has made many people go WTF?!?! It seems to be true on the 1.8 and 2.8.

My PES 2.8 reads 82% with the pedal down. Indeed the last inch of pedal travel does pretty much nothing, the plate is wide open and the throttle reading is 82%. Did this stock too. My stock passat 2.8 - same thing.

I believe that Clark (back when he posted as an individual and not as part of Turbo5) got annoyed with this truth and actually took off his trottle body, filed off a bit of the hardstop for the throttle sensing potentiometer and got his to go to 90-something percent. This resulted in a bit longer injector pulses. Perhaps in more high end power. Perhaps just running rich.

Thing is it seems to me that the ECU is designed to get normal maximum length pulses at about "80%" - adjusting for the usual lambda and stuff. And to me, if you've got max injector on time, and max throttle plate open, then that's max. If it's called 80% on the VAG, that may be confusing, but not something to worry about.

I would look elsewhere for the problem.

-Zain

zain

I never see "FULL" on the text of my VAG

DocWyte

I could care less about the fact that it reads 87%, that's normal and fine.

However, it DOESN'T read "full throttle" when I have the pedal floored! It only reads idle and part throttle. So even with the t-body up against the stop, the VAG still reads part throttle.

So the t-body isn't recognizing full throttle as such. So it can't tell the ecu what it's really seeing, so the car runs crappy.

The VAG should read idle, part and full throttle, regardless of the percentage that it's reading at full throttle. Mine *never* reads full throttle, and I've tried 2 t-bodys, several ecus and several chips...

DocWyte

Maybe you have the same problem as me. How's the car run? What's your boost like?