S2 ABY loses power over 4000rpm

[macspring]

None of us are perfect. You, Dave (), or me.

Every day is a school day for all of us.

As suggested, connect stuff as the factory intended and then see how you get on, and report back.

A new n75 should not break you, if you can afford petrol for an S2.

Girlfriend could be a keeper, if she's ok to take photos of your car's engine for you.

[Quattronaut]

the engine is original without MTM 303 chip

Excuse me- but DOES the car have the chips inside or not? And which chipset ever is inside- BOTH Chips, or may be they are combined-e.g MTM Ignition with stock MAF CHip? If stock Chipset is used- really stock, and did in run proper in any car before? ABY Motor?

If I got it right, the car didn´t run proper when you bought it. What Chips where inside at that time? Then you installed the MBC, and it ran proper- with what chips? And now it agains runs weak?

First thing:
Did you read out fault codes? I would read them, before changing parts without knowing anything. When there is no fault code, then it may be knock sensors as posted before, because damaged knock sensor won´t give a fault code- and it´s very possible that they faulty "knock" on higher rpm´s, and on higher temperatures, exactly as you described it.

What pressure is shown, when the car loses power?

[Alticity]

New n75 i ordered, going to change it friday

ABY engine
The Mtm 303 chips are installed, fuel and boost.
When i bought it was original. I didnt have any experience to say if the car was okey back then (this is 3 year ago). But i remember when i bought a bar meter i only got 0,6bar. Then i bought mtm chips and mbc.
After i installed mbc and chips and got pressure on 1,2bar, it started to **** up on 4000rpm

The pressure is 1,2-3 bar. The pressure do not drop when i hit 4000rpm.

No, but im going to a garage next monday to change fuel filter, can check if they could read out fault codes.

The car works great time to time, but sometimes its dies on 4000rpm. One time it died so bad the rpm stopped completely, on full throttle and 1.2bar.

Its hard to remember, this was back in 2011, ive been sick of this problem so from time to time i has displaced it....

[Rikki Kitto]

This sounds like boost leak issues to cut completely just as boost is coming on hard

[GazzaG60]

wire iot to factory, test it.#

see what happens and let us know.

these cars are old now and any number of issues could be present.

[Alticity]

Update

Finally back home with the car!

Checked the MAF connector, looked totally fine to me. Picture of the connector below.

Checked the knock sensors and the cables. And the sensors where completely loose. Tried to thigten the bolt, but the bolt was to long (picture below). So changed the bolts and thigtened it with 20Nm The car now runs smoother idle, and I reckon this was the reason it stuck at 4000rpm.

I bought a new N75, but when i opened the packege the N75 was broken!
Going to call the dealer on monday, hopefully i get a new one

I wired it up with the mbc in paralell with the N75 (used the old one), just like the drawing below. And with the mbc completely closed i got about 1,2 bar. Tried to open the mbc, but the pressure wasnt going any noticeably higher.
Then i tried to thigt the wastegate spring, then i got about 1,5 bar, but the pressure wasnt stable, it was falling pretty much at higher rpm, and the car was going in protection mode.
I forgot to say earlier i have a 1,9bar wastegate spring. http://store.034motorsport.com/audi-...bar-20608.html

Should i change back to orginal spring to get a more stable 1,5bar pressure?
Or how do i get 1,5bar stable on these cars?

I also still have the Forge resirk valve installed.

Below its a picture of the car in last summer in Norway!

Thanks for all the help so far!!!

[UrS4boy]

... I forgot to say earlier i have a 1,9bar wastegate spring. http://store.034motorsport.com/audi-...bar-20608.html
Should i change back to orginal spring to get a more stable 1,5bar pressure? Or how do i get 1,5bar stable on these cars?

I really don't know why I am responding to Mr. Don't Tell the whole story at the beginning but....

Yet more info slowly leaked out to us. *IF* you had told us that in the very beginning, I would have told you that if you install the 1.9 Bar WG spring from 034, you need to wind the adjustment screw on the very center top of the WG cap ALL THE WAY UP (out) at the beginning, and then slowly (trial and error) give it a turn in until you reach a point where you get massive cut-out and bucking on WOT, then back the screw up until the cut-out and bucking on WOT just goes away. I had this on my RS2'd AAN and the solution was as above.

BTW, as for your MAF connector, from that photo, it looks like ALL five female pins are pushed too far back into the connector housing. Might not be true but that is what your photo shows me.

[Alticity]

Glad you're back!

The wastegate spring is all the way back now
But what shall I do with the mbc then? Just have it closed and adjust the pressure with the wastegate?

Sorry for bad picture of the MAF connector, new picture below!

[newsh]

Boost pressure is controlled by the ECU software in conjunction with the WGFV (N75). If the software was written for a 1.9Bar spring then you need a 1.9 bar spring, if not then you shpould use a standard spring. The ECU will always try to make the boost that is written in the software unless something is wrong or not working then it will either fail to make full boost or decide not to make full boost.

Start the car and look into the engine compartment, try to get a finger on the WGFV (take out the headlight if neccessary) Blip the throttle, you should hear/feel the WGFV go clickety click.

[UrS4boy]

MAF photo is better. Pins seem to be in correct position.

As for the MBC, what should you do? Two words: søpla kan

This is the same connector as the MAF (used also for the throttle position switch), showing one pin pushed back (needs to be pushed forward):



Your MAF connector:



My MAF connector:

[newsh]

You ned to make sure you don't have any leaks in the inlet tract (we call this "doing a boost leak test")

Don't have a poke around under the bonnet then come back and say "all the hoses look ok" You need to pressurise the inlet tract to 1Bar and see if it holds it. Do a search on here to find the method.

Your MAF connector may look fine, mine did, clean it anyway with some good quality contact cleaner. You can have a tiny spot of corrosion right on the contact area of the pin or socket which will affect the reading. Read this http://www.s2forum.com/forum/showthread.php?t=24544

[Quattronaut]

I think, MTM software normally is for stock WG- springs...but not sure at this point. I would try to figure that out, contacting the guy who sold the software, or even contact MTM. Maybe you should read out the software number before, so you can tell MTM what software it exactly is.

For searching motor problems, I would throw out REALLY EVERYHING that is not stock. MBC, second N75, its hoses and wires- everything. Stock engine, stock WG, stock boost controling system, if possible stock ECU. Be sure that whole system is in good condition- everything that was cut, or adapted, or extended when installing the MBR or someting else, throw it out, replace it. Every hose, wire etc that was cut to install, and now will be picked together again when tha stuff is thrown out, can cause failures, so don't pick together-buy new.

Leave the pressure gauge, if it's a good one, but check the installation.

If the car had only 0,6 bar, there already was a problem. Tuning a faulty system--> bad idea. Faults tend to increase when motor is tuned, not to go away :-)

Then, with stock car, I think, issues should be found fast, and then build it up again, part for part.