STU3Y

Active Member
Nov 11, 2013
1,271
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Kent
I am trying to do some logging with vcds but struggling to plot result on a graph.

I think I have finally managed to do the boost results but don't really know whether they are normal or not.

I can't remember if these results were in 3rd or 4th gear. I will do more if necessary when I get a chance.

What do they mean, and if there is a problem what is the solution?
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What engine is it? mapped?

200-250mb overboost, then the ECU gets it back on track. Usually a result of either a slightly sticky VNT, or a generic map not tailored to the car, resulting in poor boost control

You need to plot the RPM on the graph too, and the N75 on a secondary axis.

Have you got a copy of the CSV file? Dropbox link maybe?

*edit* Too slow typing my response ;)
 
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Seat leon tdi ref sport 140. As far as I know standard map and turbo is less than 6 months old
 
One thing I thought I'd mention my old turbo used to allow me to put the car in 6th at 50mph and still be able to accelerate easily even up steep hills. The new one has a lot more lag in the same circumstances takes a good few seconds to build it up before coming into life as if I've gone up the gears to early. Could this be related?
 
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No genuine garrett turbo recon by turbo technics (or dynamics) cant remember which. Could it be anything to do with the actuator rod being adjusted incorrectly.
 
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If it's a recon unit it won't be genuine. Don't see many recons that are set up correctly.

The turbo geometry won't be set up correctly, which means the boost profile isn't in line with what the ECU is expecting from the map. The ECU will follow the map until it exceeds it too much, then it will interfere and bring the turbo back under control, hence the spike and the wavey look of the graph whilst the ECU regains control
 
Sorry I meant rebuilt from a genuine garrett. How do I get it set up correctly
 
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Second results from vcds, this time for egr. Again to the experts for their opinions as look a bit far apart to me.
Causes and solutions?
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Logging of boost and adjustment of the turbo to set it up correctly, will most likely void any warranty left on the turbo

EGR graph does not look right at all. Have you logged MAF specified vs MAF actual? Looks like WAAAAAY more EGR than there should be
 
I believe over boost was one of the reasons for turbo failures on 2.0TDIs. As previously mentioned, the vanes get clogged and cause the actuator to stop working. If its a rebuilt unit, could be the actuator preload not being set correctly for the car. maybe been set to suit a 170 instead of 140 model?? just throwing ideas up there.

going off your boost graph, the ecu is asking for 19.5psi peak boost but getting 23psi. Its not a massive amount 3.5 psi, the graph is making it look worse than it actually is.
 
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Logging of boost and adjustment of the turbo to set it up correctly, will most likely void any warranty left on the turbo

EGR graph does not look right at all. Have you logged MAF specified vs MAF actual? Looks like WAAAAAY more EGR than there should be
The writing you see in the graph is exactly as It shows on vcds, i just ticked the boxes for egr rather than maf in the advanced measuring blocks.

What would cause this? My egr is clean as I only had it off recently.
 
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Not just overboost, any increase in turo pressure finishes them off, due to the fact that it is a shite turbo and can barely handle it's original boost pressure. Increasing it (with a remap or from overboost) just finishes them off

Stu, apologies i didn't word that well. I can see what you've graphed is accurate, i meant that something is seriously amiss there. That is a LOT of EGR flow, the usual maximum is 750-850 but only at a limited RPM under certain conditions. A MAF reading to go with this will help give a better understanding of what's going on, along with more data on the graph, there;s no inidcation of load, whether thats full throttle, cruise etc
 
That was in 4th gear at full throttle. I am not very good at making the graphs as I only have 2007 excel which doesn't have the chart wizard.

I did a few different log files haven't managed to put any of it up yet. Cant remember what I added to the list.

Might be easier if you just tell me what to add and ill do a new logs, one for turbo boost and one for egr. Plus anything you think will be good to check the cars health?
 
Are we looking for anything in particular? MAF, Fuelling and boost as the usual things to log, EGR too if its active. Things like RPM are required on every log, and if mixed driving, throttle request is also needed
 
I bought vcds to help diagnose my non start issue from my "car won't start" thread.
www.seatcupra.net/forums/showthread.php?t=404097

However after fitting a used tandem pump and changing fuel filter its now turned into a hot start issue.

As such i was trying to log things in order to find a fix.

I was also looking at this thread.
https://sites.google.com/site/1810martin/vcds-and-pd-tdi-engine-health-check

These are what I've done so far, as I said I don't really know what I'm doing so instructions of what to log would be great.

With regards to your earlier question of logging maf actual vs specified. I do not have this option in vcds. There is only maf specified, however as you can see in the bottom graph egr is measured via maf anyway so is the same I believe.

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Cleaned MAF and re logged
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