Correct AFR

[newsh]

ok guys thank you for the ideas, that does make sense regarding the small leaks
and yeah sorry for hijacking the thread I thought that was relevant regarding the afr i was about to look at
my 3b is in audi 200 20vT, am I welcome here?

Yes of course, we love everything 5 pot turbo

[domas]

ok guys thank you for the ideas, that does make sense regarding the small leaks
and yeah sorry for hijacking the thread I thought that was relevant regarding the afr i was about to look at
my 3b is in audi 200 20vT, am I welcome here?

[andy10v]

You will never hear small leaks with the engine running, far less loading it like that, I would not bother.

This is kind of going off topic, I would start your own thread, list faults, tests done so far, any fault codes, exact car spec etc.

[andy10v]

CCV is PCV (breather pressure control) valve, right?
Then why do I want to disconnect it? is there a particular reason breather is not tested? So you mean that I have to bung the hose @ huge maf connection (bottle works great here) then bung the disconected line to pcv, and apply pressure to MAF boot, where PCV line was?

Yes PCV.

Blank where the PCV goes into the maf hose (wheel bolt head works).
Just leave the PCV open.
Put a big plug with a schraeder valve in the MAF hose (MAF and airbox top removed)

Pressurize the system to 1 bar say (I normally pressure test to the peak boost the car will see, not saying its correct but it works for me)

Large leaks will be audible, use soapy water and a spray bottle to find other leaks. Check all joints, ISV, vacuum lines, injectors seats etc.

If you have a lot of air loss through the wategate line you can disconnect it and plug the line temporarily.

I would check you cannot blow through the DV, and check the diaphram holds vaccum. (you pressurise both sides if it when leak testing including the MAF hose)

I think you can low pressure test with the PCV connected to check for leaks, but confirm that first, I dont as I use a catch tank.

[HMS-S6]

You need a 51mm hose ��

[domas]

What is the intake diameter of my k24?

[domas]

well that's what I heard ;-] don't judge me just saying.
I am looking in the leak testers right now, they don't even cost the quoted 100pounds. Probably ordering one today.

[HMS-S6]

Be sure to tie up your horse outside the garage for this test - sounds like some cowboy engineering to me

Yeh! Sounds like nothing I'd out my car through. Specially since some leaks you will NEVER hear. Plus a boost leak kid is under £100 on the net that'll do the job!

[S2central.net]

From what i know, there is also a little harsh way to test it for the leaks, you an lift the whole car, put it in a gear, get somebody to listen under the hood for blowing hoses and slam the throttle and the brake at the same time, and modulate the brake to keep rpms at turbo-happy level. Should not be used for extensive time though. I don't have a lift and am not a big fan of this method

Be sure to tie up your horse outside the garage for this test - sounds like some cowboy engineering to me

[domas]

I will sure do when I am at my car in the end of December.

From what i know, there is also a little harsh way to test it for the leaks, you an lift the whole car, put it in a gear, get somebody to listen under the hood for blowing hoses and slam the throttle and the brake at the same time, and modulate the brake to keep rpms at turbo-happy level. Should not be used for extensive time though. I don't have a lift and am not a big fan of this method

I am planning to make an adapter for the turbo inlet, any ideas what piece of rubber to make it from? suspension bushing with a vband around and a hole in a middle with tire valve?

But do you guys agree that in my videos it does look a little strange that boost raises to demanded level and then drops?
All other times I had proper leaks, it would make a typical blowing sound and would not raise the boost.

[HMS-S6]

I took this approach of OVER thinking everything and it cost me just short of £5,000! Pressure test it first instead of assuming then at least you can rule out for sure the most common problem these cars have.

[domas]

no no - it started doing this out of the blue. Was okay before. I tried it with other good known ECU from ben swann with 3 bar sensor. It boosts to 1,6bar and then drops in the same manner 0,1bar /sec

[prj]

Software is **** probably. If the RPM's are constant and it's doing this, it means it's overboosting and ECU is cutting all boost.

3B has a 200kpa MAP. Unless that's been changed it can't even see more than 1 bar boost. Not that changing it with random chips is a good idea.

[domas]

So it should be approx 0,85 lambda.. Lets see what I can find out

[S2central.net]

Seems like boost leak to me. Assuming 3B mixture at WOT is much like ABY then expect sideband O2 readings in mid 12 range. If you see AFR dipping much below that it (i.e. too rich) it would correlate with a boost leak (as MAF measure more air than was actually consumed).