Think I've fixed it?!

[S4_dan]

Cleaned the 2nd hand MAF up, cleaned the EGR valve and unplugged the electrical connector on the EGR/N18 valve.

What a difference in driving it now! So I did some logs with EGR electrically unplugged:





And with the EGR electrically connected..DTC codes cleared.....boost felt stronger and smoother here:





Does anyone know why my turbo is taking a short while to meet the requested boost level?

It felt the nicest to drive since owning it today. So must be heading in the right direction....

 

[S4_dan]

Also, no lights on the dash with EGR unplugged?! Thought it would be on 2002 model.

 

[stu_m]

that boost curve looks pretty fine to me

the boost comes on at about 1500 rpm then drops off and holds a steady line

if you still think its slow to spool then give it clean with mr muscle oven cleaner and see if that helps

 

[S4_dan]

that boost curve looks pretty fine to me

the boost comes on at about 1500 rpm then drops off and holds a steady line

if you still think its slow to spool then give it clean with mr muscle oven cleaner and see if that helps

Done that, I removed a few weeks back, stripped and cleaned it. Think I'll look at another turbo then a remap.

 

[stu_m]

I dont think you need another turbo to be honest!

a dyno run might be worth it for a power run to see what its putting out now and that will give you an idea if you have a problem

 

[stu_m]

have a look at this scroll down for boost etc

https://sites.google.com/site/1810martin/vcds-and-pd-tdi-engine-health-check

 

[desertstorm]

I still think you have an issue with the MAF.
Can you get one from a working car?. What value do you get from the MAF at idle ?
The MAF readings are low because the MAF is faulty or there is not enough airflow being generated by the turbo because the VNT isn't being fully engaged.
Have you measured the vacuum level being applied to the turbo actuator at idle should be around 22 In Hg.
A lot of petrol boost gauges measure vacuum if you have one of those lying around you could use it.
I have attached a smoke map from the ECU that is on your car. Ignore the 180bhp this is the AKE 150bhp file.
You can see fuelling is limited by the MAF reading. On your car to get maximum power you need approx 46mg of fuel to get that you need a MAF reading of at least 750.




Karl.

 

[S4_dan]

The turbo whistles from 1100rpm, although no play in the shaft etc.



When I was at idle the maf was meeting the specified and actual measurements. Also whilst driving along steadily it was meeting the values. Sometimes blipping slightly over and slightly under, but mostly ****-on.

So if the air is down slightly then it brings me back toy.initial thought of the actuator not being setup correctly as the turbo vanes are clean.

The duty cycle appears to be spot on meaning that the actuator operation is working fine. Again leading to the actuator/vane position incorrectly set.

I will try and source a new maf, still waiting for Stoke Audi to.get back to me. But the car drove the best it ever has done yesterday. Didn't have to down change from 4th on a steep hill at 1400rpm, it just kept it at those revs and pulled up nicely. Before I would be down changing to gets the revs above 2k just to stop the car from slowing down.

I do appreciate your comments. I hope I can fully solve this and make the Audi a pleasure to drive once again.

Cheers.