Little. Blue. Different.

[JET]

That does seem weird, throttle body is opening 100%, right? Other than that it seems like it must be a restriction somewhere.

[scheides]

TPS does hit 100% in logs and if I twist on the black piece that the cable attaches to it does open the butterfly all the way....maybe I'll have someone sit in the car and push the pedal all the way down and take a look. What on earth would cause that though? Sounds pretty far fetched. Still, I'll test it out.

[FattyBoomBatty]

Maybe the carpet got bunched up under the pedal.

[niterydr]

Same/similar intake setup? Intercooler piping clogged (maybe a rag in a pipe?).

Dumb questions, but it does seem like an airflow restriction if ignition and cam timing are perfect and compression haven't dropped.

[scheides]

Ok, I did compression test tonight: 170 167 170 176

Also I did a leak-down test. I'm not 100% sure I did it right or that my harbor freight unit works so well, but I came up with: 15 15 15 15, dead even across the board. However, no air coming out of TB, no air coming out of exhaust, but def air coming out of dipstick/oil fill cap :( Where could it be coming from? past the rings?

I think I'm going to have shane do a comp/leakdown test for me to just get a second opinion. Maybe my fancy catch-can setup sucks/is broken? Not sure yet, but I'm gonna get to the bottom of it :(

swanny, I still have a glimmer of a doubt in the back of my mind on the rag in the FMIC theory.

[FattyBoomBatty]

throttle was depressed completely on the comp check? Those numbers don't seem too bad to me. Pretty much all the same (only a small percentage difference).

The leakdown tester is a strange thing, but how I read it was by checking known good compression cylinders then checking the supposedly bad one(s), and comparing the pressure required to keep the needle in the green area/zero on the second gauge. On the bad cylinder it took more air, plus on the dude's engine we could hear it coming out the exhaust pipe (bad valve). The whole time we had pressure in the engine, it was leaking past the rings, but his compression was perfect on 3 of 4 holes.

If I were you, I wouldn't worry about the rings.

[Kracka]

15 across the board is pretty good for a leakdown test assuming you performed it correctly!

[niterydr]

Ok, I did compression test tonight: 170 167 170 176

Also I did a leak-down test. I'm not 100% sure I did it right or that my harbor freight unit works so well, but I came up with: 15 15 15 15, dead even across the board. However, no air coming out of TB, no air coming out of exhaust, but def air coming out of dipstick/oil fill cap :( Where could it be coming from? past the rings?

I think I'm going to have shane do a comp/leakdown test for me to just get a second opinion. Maybe my fancy catch-can setup sucks/is broken? Not sure yet, but I'm gonna get to the bottom of it :(

swanny, I still have a glimmer of a doubt in the back of my mind on the rag in the FMIC theory.

15% is decent, but exactly the same figures on every cylinder is freaky.

I don't usually bother with compression numbers if the leakdown is good. My Audi leaked between 12-3% fyi, each cylinder was a bit different.

Could be a bit of leaking past the rings, but with 15% you usually don't notice it that much, compression numbers look decent. I wonder if your measuring instrument is accurate. Maybe have Shane double check it like you mentioned.

[MustGoFaster]

+1 on those numbers being good, but a little odd. As for where it's going, at 15% I wouldn't worry about it to much.

[scheides]

Ya, its not like its like WOOSHING out the dipstick or oil fill cap when I open them with the pressure applied, its just a very faint whisp of air, and then I can hear air coming out if I open/close the cap repeatidly.

On the compression test, I didn't realize you were supposed to open the throttle 100%, is this true? Could this affect the numbers in a good or bad way?