Urs4 running lean . Lambda, MAF, pressurer regulator?

[Isaksa]

I dont think it´s on the pressure side. I think it needs to be on the fuel side. You can always disconnect the fuel rail with the injectors and get hoses from the injectors to bottles just to see if there running the same amount of fuel in a minute or so.
This seems that it works fine on idle, but with boost it gets lean, so it is not getting enough fuel. There are not too many reasons for that, either the pump is getting dead, the filter is dirty, or the injectors are.. Are you sure that the pump is really changed? It is not too nice job to do, check the cover from the gas tank. You can see it in the trunk and if it has been opened, it should show in this old car.

Yes, i can see that someone has been inside the tank.
But it is har hard to tell if it is an new pump, it is all clean inside
They also have mounted new 12v wirings to the pump from battery trough relay to ensure that the pump gets enough power.

Is it possible that it is my MAF that is broken, after it came som water inside?

[Isaksa]

Checking that the wideband is ok.

Video

https://www.dropbox.com/s/ag5q0smhleepfya/2014-01-04%2023.00.41.mp4

[Ugemi]

Take the maf connector of, it goes on a safe program and should be really rich.

[S2central.net]

If ECU has been properly mapped for the 440cc injector, the FPR is use and that MAF pipe conversion (the trickiest part as the load measurement routines are not at all simple - Dmitri is the only guy I know who has got his head around that stuff properly) and Motronic lambda adaptation is left untouched then you should see AFR of 14.5-14.7-14.9 at idle and steady cruise.

On high boost you should be seeing high 11s or low 12s - though some folk like to see richer in some exotic installations.

If mixture used to be good and now its not then I would look to get the pump tested, check the filter is good and (as someone else suggested) - check the boost connection to FPR is good at the IM. Maybe try another MAF too.

[UrS4boy]

Iv'e been trying to check for leaks, but how do you guys perform a leaktest? Do you disassembly the airfilter and insert air that way, or do you block innlet on turbo and insert air in any vacuum hose? Regards

Have a read on this (found by searching on "boost leak testing"):

http://www.s2forum.com/forum/showthread.php?t=63974&highlight=boost+leak+testing

[Isaksa]

Temp sensor (G62)
Measured at 4-5 degrees celsius

according to this :

[Isaksa]

I will make a leaktester unit at work tonight, fitting where the MAF usaly stands. anyone remember the diameter of the valve that all you guys have in your tires?

[UrS4boy]

[IMG] Temp sensor (G62). Measured at 4-5 degrees celsius

That is kind of funny. I am chasing my own hard start-when-warm issue and I checked my G62 yesterday at 3C and got 4650 ohms. I made a post on my home forum, looking for a better diagram than this. Looks like you inadvertantly just posted what I needed. Thanks.

http://forums.quattroworld.com/s4s6/msgs/269094.phtml

Photo courtesy of Timbo on vwvortex.

[Isaksa]

Hehe, Nice

[Isaksa]

Ready for leakseek with homemade tool :-)



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[Isaksa]

If i pinch the vacuum to the FPR, or insert pressure with external compressor to the pressure regulator. Can i see on the afr gauge, If the fpr is working as it should?
Or do i have to read lambda values in vagcom?

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[S2central.net]

It would be wise to get a fuel pressure gauge fitted - if only temporarily - it is possible the aftermarket adjustable one has failed you. You should see the fuel rail pressure rise and fall linearly with pressure or vacuum applied to the manifold (air) port… or thinking another way - you should always see X + ambient pressure on the fuel rail where X is the nominal/adjusted reference value (X = 3.0bar on 3B ….. 4.0bar on ABY/AAN …… 3.8bar on ADU)

Do not waste time trying to read lambda values at WOT from VAGCOM as they are nothing like accurate - ECU comes out of closed-loop mode under full throttle and the mixture you get is what is programmed in the maps for the relevant engine speed and load point and OBD does not attempt to measure it. The WB O2 sensor and display is what you need to rely on for accuracy under high boost conditions.

Like I said before - if it ran nicely rich before at WOT on the same setup, then something has failed regarding mixture preparation:

- Fuel Pump or supply voltage
- Clogged Fuel Filter or Fuel Line - check the flow of fuel at engine into a bucket from pump with 12V applied for 15 seconds
- Fuel Pressure Regulator
- MAF / Wiring
- ECU / Wiring for the injectors

[Isaksa]

This is cyl 1..

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[Isaksa]

All 5

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[S2central.net]

That doesn't really tell anything - get a fuel pressure guage fitted !