Boost problem

[igor136]

Hello guys.
I have a problem with my urs6 aan. Boost is 0.7 ( 1.7 on display) bar at 5000 rpm.
If I disconnect the hose to the wastegate have a 1.2( 2.2) bar. It's just a test, of course. Then the ECU cut gasoline pump. I have reviewed intercooler and hoses and I think I have no leaks. If I disconnect wires from the N75 valve, no change. Today I changed the one-way bleeder valve and the pressure regulating valve. Same thing. Disconnect MFTS and the same thing. I washed the MAF sensor with isopropyl alcohol. No fault codes. If I do diagnostics manually, then I hear the N75. If on the idle disconnect the N71, then ECU automatically disconnected N75is . I think that's normal.
Pop off is the new, of course. Spark plugs are new. What do I do, has anyone an idea?
thanks

[UrS4boy]

AAN boost leak testing

.... I have reviewed intercooler and hoses and I think I have no leaks.....What do I do, has anyone an idea?

Thinking you don't have a boost leak does not mean you don't have a boost leak. You have to test with pressure, say 1 Bar, to confirm.

Read this all the way through: http://www.s2forum.com/forum/showthr...t+leak+testing

[igor136]

Thinking you don't have a boost leak does not mean you don't have a boost leak.

Hehe, I knew you'd say that. Thanks for the advice, I appreciate your opinion.

[igor136]

Today am tested intercooler and hoses. No leaks. But ... pop off valve keeps the pressure up to 0.5 bar. Then starts to leak. I bought it new because the old did not hold a vacuum. I bought it through eBay as the original. It seems to me that it is not original, although it has Audi's signature.

[igor136]

Regards guys.
I'm going crazy,
Blow off valve that I bought through eBay is not good.
The number is 06A 145 710 P, not N. It's a little weaker.
Now I ride with the original pop off with a broken membrane. I will buy a new valve this week.
Next, I measured the resistance of the Coolant Temperature Sensor.
The resistance must be 2800 ohms at 20 degrees Celijus( 1930 ohm to me) to 200 ohms to 100 degrees (210 ohm to me).
Air Temperature sensor resistance should be 500 ohms at 25 degrees and 600 ohms to 100 degrees. For me it's 521 to 555 ohm.
All this seems to be fine.
But ... Throttle Potentiometer resistance is a little different.
It must be 1K ohm when it is closed and 2.8kohm when fully open (full throttle).
For me it's 1K ohm when closed and 2.4 k ohms when open. It is 400 ohms less. Does anyone have experience about this, so this may be the reason for a small boost, 0.8 bar ? Or just pop off the problem?
Please help
Thanks

[hotibi]

I think only the pop off valve is the problem. When our pop off valve membrane was teared the boost was drastically reduced.

[igor136]

Still not my friend. I bought a new original pop off. Same thing.
I decided to buy the N75 valve. On my car is 034906283H and it costs 180 euros. It is very expensive. I thought to buy another but I found this:

http://www.seatcupra.net/forums/showthread.php?t=22403

What do you think guys, which is the best valve, the original or a replacement?
Is this good?
http://www.ebay.de/itm/N75-Tuning-Ve...item5b01459f03

But, it is not H.
Thanks

[Majorcina]

Mislim da mozes i taj sa ebay-a kupit

[igor136]

Today I bought a new N75. The leg straight in the balls. The same problem. 1.8 bars on the display.
Does anyone know how to check the MAF sensor? ( I measured the resistance and the voltage on it and everything is within the tolerance limits. I drove the car without it and did not want to go.)
Because I have a little problem with the engine speed. Idle between 740-800 rpm and if I hold the throttle at 3000 rpm then 50 RPM speed varies up and down.

[prj]

1. With N75 electrical plug disconnected you should have 0.4 bar boost through the whole rev range.
Verify it is so. If it is not so, something has been done with your wastegate.

2. You still have not done a boost leak test. Do a proper boost leak test. Pressurizing everything including the intake manifold starting from the MAF. What you have done so far has been a waste of time.

3. Depending on temperature conditions 0.8-0.9 bar is ok at 5000 rpm.

4. Instead of pressing only the fault code button in VCDS, use measuring blocks. Make sure when you push the throttle to the floor you see at least 90 in the TPS measuring block, make sure your IAT and ECT readings are correct. Also check the barometric pressure measuring block, make sure it is not stuck at 700mbar.
Measuring resistances borders on idiocy when you have the diagnostic function of the ECU telling you exactly what the ECU is seeing.

And finally, please don't pm me for random things like this, do your homework better and ask your questions on the forum, so that others may benefit from the knowledge in the future.

[igor136]

Thanks Prj.
Today I tested Wastegate. He begins to open at about 0.4 bar and fully open at 0.8 bar. The membrane is like new. Is this a problem?

[220bhp]

Dimitri I find your brutal reply's a source of great entertainment. I just love the fact that you take no prisoners

[UrS4boy]

...And finally, please don't pm me for random things like this, do your homework better and ask your questions on the forum, so that others may benefit from the knowledge in the future.

Don't blame igor136 for contacting you. I have been trying to help him via PMs after he contacted me asking me for help. I did help him but, in the end, because I have no immobilizer ECU experience (none in NAmerican C4UrS5/S6s), I encouraged him to PM you to ask specifically which ECU he should use to replace the 551B (UrS4 autobox ECU) that he currently has in his UrS6 with immobilizer key. Apparently he asked more than that and/or you don't know the answer.

Specifically I said to igor136:

"If your car is manual transmission I think you need to look for one of these:

551AA UrS4 non-immo, Europe and America

551C UrS6 incorporates all software updates from RS2, different codebase, more diagnostics

551E UrS6 has a small tweak to fuel on cold start

I can't help you for sure on the immobilizer issue. Contact prj (dmitri) here on the S2Forum via a private message and tell him your story and ask about the correct ECU for your situation."

I thought it would be easy for you to help him. I guess I was wrong.

[Majorcina]

I just wanna to confirm that Dave(UrS4Boy) always try to help as much as he can,even to reapit same thing 2-3 times,so i belive if he could help he would-i know he helped me xxx times

[igor136]

When I unplug the cable from the N75, the boost is also 1.8. No 1.4. It was strange. Strange is that the car at 3000 rpm goes well and I feel that the 3500 losing boost.
Now I put the pictures that I sent colleagues Urs4boj and Prj.
My ecu is for a car with an automatic transmission. My car is manual. I do not know if that's a problem.
I have a vagcom measuring car at idle.