Very poor mpgs! Faulty maf or map sensors?

[C50]

I have an Ibiza Cupra Tdi which just had a new turbo fitted.

I seem to get average 30-35mpgs on the motorway driving super carefully, whereas before I was getting near 50mpg driving normally with extra throttle when needed.

I drove

down the road, nothing crazy​

and did a quick VCDS log

of the actual vs specified mass air and air pressure​

and uploaded it to see using the link kiksu.net/vcds-graph/

However, I don't understand what I see so would somebody who knows their stuff see if anything looks not so good please?

my short csv log is

https://www.dropbox.com/s/0raspo2lic148xz/LOG-01-003-011-xxx.CSV?dl=0​

​

Thanks

 

[Sturtz1987]

I'll convert it into a chart for you tomorrow and see what it looks like.

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[Sturtz1987]

Did you get the vnt rod set on new turbo?

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[C50]

Thank you!

Nope I didn't I assumed everything would be set up already as it's a reconditioned turbo. It seems to work and boost fine.

I did notice the stopper on the new one being over twice as long and would stop the actuator rod earlier. The adjusting nut was tight and awkward to get with the actuator bracket bolt head in the way so I assumed that was set up also. See pics

 

[C50]

Anybody able to have a look please?

I'm afraid of wasting monies on map and maf sensors if they seem ok

 

[Legojon]

It's been a while since I've done any diagnostics. So take this with a pinch of salt. But I thought you'd need to record throttle position as well. Something like, actual reading is based on requested and adjusted by throttle position. So to get actual = requested you'd need your foot all the way to the floor. However I could be thinking of fuel requested vs actual. So apologise if this makes it harder to diagnose.

 

[Legojon]

Ah... this is from Rosstechs guide.

Air system part I: MAF

• Go into Engine measuring block 003
• Start Logging data
• In a high gear (4th/5th), give full throttle from 2500 rpm up to 3500rpm.
• Find and Open the Log file in Windows Explorer
• Graph MAF actual -vs- rpm in Excel
• The MAF is OK if the actual value is at least 850-900 mg/h at 3000 rpm.

 

[C50]

Ok, I'll give that a go.

The only thing that pops to mind... there was a huge amount of oil in the intake hoses when the old turbo went hence thinking it could be the map sensor. I flushed the pipes out with unleaded petrol so perhaps that could have damaged it?

 

[Legojon]

Does the MAP sensor show atmospheric pressure when the engines off?

 

[C50]

Does the MAP sensor show atmospheric pressure when the engines off?

No, I believe it only shows a value when the engine is switched on and running

 

[Legojon]

No, I believe it only shows a value when the engine is switched on and running

Hmm, is that with the electrics on?

 

[Sturtz1987]

Anybody able to have a look please?

I'm afraid of wasting monies on map and maf sensors if they seem ok

I'll put some coal in the laptop and fire it up and convert it into a graph and see if that makes more sense. I had to take my turbo in to get actuator calibrated and set on machine.

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[C50]

Update: I bought a genuine MAP sensor and cleaned my MAF sensor; but no improvement.

The rubber boost pipe from the turbo has developed a hole now