Urs4 running lean . Lambda, MAF, pressurer regulator?

[Isaksa]

Spray bottle and soap water. You should see bubbles

I found a leak today. There was leakage of a seal in WG, but this is probably not my problem with running lean..

Iv'e noticed this problem on my way home today..
If i push the throttle, and aim at 2000rpm and then keep steady, it start to bounce 500rpm up, and then down again. It's the same at 3000rpm, Afr gauge shows fuelcut when rpm goes down.
Can this be my problem?

I have added a video:

https://www.dropbox.com/s/sjlsmhgerqx8zty/20140219_213544.mp4

[newsh]

.

Iv'e noticed this problem on my way home today..
If i push the throttle, and aim at 2000rpm and then keep steady, it start to bounce 500rpm up, and then down again. It's the same at 3000rpm, Afr gauge shows fuelcut when rpm goes down.
Can this be my problem?

When we had this problem on a member's car it turned out that the 2 pipes on the back of the head were swapped, so the crankcase vent was connected to the inlet manifold (and carbon can to the MAF hose). This can also happen when the "one way valve" in the PCV crankcase breather system is broken.

Are you still running the PCV system and or the carbon can system?

[Isaksa]

When we had this problem on a member's car it turned out that the 2 pipes on the back of the head were swapped, so the crankcase vent was connected to the inlet manifold (and carbon can to the MAF hose). This can also happen when the "one way valve" in the PCV crankcase breather system is broken.

Are you still running the PCV system and or the carbon can system?

I am using PCV and a carbon catch can. I believe it is this one.




So in your case, the engine did get more air (because of leakage) in pcv system, so rpm started to bounce like min did?

[newsh]

I am using PCV and a carbon catch can. I believe it is this one.




So in your case, the engine did get more air (because of leakage) in pcv system, so rpm started to bounce like min did?

Yes, if you tried to hold the engine at 2000rpm it would bounce by about 500

You need to look under the back of the Inlet manifold for the place where the 12mm and 20mm hoses join together, inside the join there is a one way valve, this might be broken.

Alternatively just disconnect the small pipe from under the IM near the throttle body and plug both sides and try that.

[Isaksa]

I will check it out right after work.
My local dealer did have this "one way valve" in stock, so mabye i just buy one on my way home =)

[Isaksa]

I will check it out right after work.
My local dealer did have this "one way valve" in stock, so mabye i just buy one on my way home =)

My problem was not the bleeder valve
I switched to my spare MAF in original housing (smaller diameter), and it did run clean when i did the rpm test. The only problem is that when i pass 3000rpm and 0.2bar boost, i already have 10.3 in afr value. I just have to find out why my car, totally unexpected just don't want the big housed MAF anymore.

But what should happen when you take of the oil fil cap , when the engine is at idle?
My motor did not even change engine sound No vacuum or pressure inside..

[Laaf]

My problem was not the bleeder valve
I switched to my spare MAF in original housing (smaller diameter), and it did run clean when i did the rpm test. The only problem is that when i pass 3000rpm and 0.2bar boost, i already have 10.3 in afr value. I just have to find out why my car, totally unexpected just don't want the big housed MAF anymore.

But what should happen when you take of the oil fil cap , when the engine is at idle?
My motor did not even change engine sound No vacuum or pressure inside..

Some oil might be thrown off the cam lobes positioned underneath the cap. Nothing more should happen.

[newsh]

My problem was not the bleeder valve

Sorry mate

I still think there is an air leak somewhere though.

I can't remember, did you do a pressure test from the MAF hose? Did it hold 1 bar?

Have you checked for a leak in the small pipe inside the ECU?

Also, maybe there is a problem with the MAP sensor? Or the hose to the MAP sensor is blocked or kinked?

[driftin jo]

Have you checked the tps switch ?

[Isaksa]

Due a small compressor, i do not get much over 1bar when testing. And pressure drops quiet fast, So i do have a leak.. I found one in my wastegate, a pretty big one. Atm i am running without bpr, i only got a hose between turbo innlet and wg (groundpressure). I think it is the wastegate diaphragm. Iv'e got more leakage inside after i have it checked.
For pressure testing, I used homemade tool, mounted before turbo. (pic)

I have been inside the car on passenger side listening after leaks, but could not hear anything. Mabye take out the ecu to be sure. But i have readings in cluster, so the hose is on the map sensor i supose

Regarding the TPS. " The throttle valve potentiometer is only used for boost regulation as the throttle valve position is a reference value for the boost control map. Boost regulation will take place when the throttle plate is open greater than 35 degrees"
Can the tps give me problems like running lean?

[driftin jo]

Due a small compressor, i do not get much over 1bar when testing. And pressure drops quiet fast, So i do have a leak.. I found one in my wastegate, a pretty big one. Atm i am running without bpr, i only got a hose between turbo innlet and wg (groundpressure). I think it is the wastegate diaphragm. Iv'e got more leakage inside after i have it checked.
For pressure testing, I used homemade tool, mounted before turbo. (pic)

I have been inside the car on passenger side listening after leaks, but could not hear anything. Mabye take out the ecu to be sure. But i have readings in cluster, so the hose is on the map sensor i supose

Regarding the TPS. " The throttle valve potentiometer is only used for boost regulation as the throttle valve position is a reference value for the boost control map. Boost regulation will take place when the throttle plate is open greater than 35 degrees"
Can the tps give me problems like running lean?

Someone had an issue with the actual switch on the tps. It has a switch that tells the ECU when the throttle is shut and a potentiometer for the position when its open.
The car in question had the exhaust manifold glowing red hot even when at part throttle
due to a faulty switch telling the EUC the throttle was shut, so from this I would conclude that it makes it run lean when the switch tells the ECU its closed when its actually open.

[newsh]

I can't see the pic on Dropbox.

When you removed the BPR (I guess you mean N75?) did you plug the hole in the MAF hose?

Also try disconnecting the breather pipe which goes into the MAF hose and plug the hole in the hose.

[Isaksa]

I can't see the pic on Dropbox.

When you removed the BPR (I guess you mean N75?) did you plug the hole in the MAF hose?

Also try disconnecting the breather pipe which goes into the MAF hose and plug the hole in the hose.

Driftin jo:
I will check tps tomorrow. But i can remember to hear a click when throttle goes to closed position, is there any other way to test this "button" ?

Newsh:
I am using a manual bleed valve to regulate boost pressure , n75 is only connected electronic. So i only got a 90dg silicon bend between MAF and Turbo, with no other connections. I could hear a leakage in the WG, and it got worse after i have checked the diaphragm.
I control the pressure like this



Disassembled the N71 Idle stabilisator valve for cleaning.
I remember to hear like a "popoff" sound on the left side on the engine when i let go the throttle after boost. Mabye this valve is defect , and allows the engine to suck air the other way?






Best Regards

[Isaksa]

Someone had an issue with the actual switch on the tps. It has a switch that tells the ECU when the throttle is shut and a potentiometer for the position when its open.
The car in question had the exhaust manifold glowing red hot even when at part throttle
due to a faulty switch telling the EUC the throttle was shut, so from this I would conclude that it makes it run lean when the switch tells the ECU its closed when its actually open.

Hello!

Do you know how to test this switch?

[UrS4boy]

G69 / F60 Throttle valve position potentiometer /idle switch information

Hello! Do you know how to test this switch?

I'm not driftin' jo but I have some info that might be of use to you:

http://forums.quattroworld.com/s4s6/msgs/20405.phtml