Turbo.

[tank]

I just replaced the clutch in my Beetle and when I put it back together the turbo isn't working. I can't see anything disconnected at the intercooler and there are no vacuum lines disconnected that I can see. Could this be because of the battery being disconnected for several days?
2000 1.9 TDI
176,000 miles
5 speed manual.

[DZLBUG]

No, the battery has nothing to do with it. Check and recheck vacuum lines, MAF sensor connection, etc.

Any codes? What are the exact symptoms?

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[tank]

I have no boost at all. I checked the vacuum lines and maf last night, but couldnt find anything. Other that the turbo it runs great.

[tank]

I don't have a code reader, so I have no idea on the codes.

[h_2_o]

this will sound silly, but disconnect the maf and take it for a drive, let us know the results.

[tank]

I took it off and there was no difference. I have oredered one and will see if that solves the problem.

[h_2_o]

if you took it off and there was no difference it is something else. look at this thread for limp mode diagnosis

Diagnosing and Fixing Limp mode for A4 1.9TDI - TDIClub Forums

after thinking a little more, go over the vacuum line diagram a couple times looking at your setup and make sure they are all correct.

good luck

edit: one more question, do you have zero turbo or just low turbo? can you hear any whistle at all?

[DZLBUG]

Originally Posted by tank

I took it off and there was no difference. I have oredered one and will see if that solves the problem.

If the MAF was functioning correctly, disconnecting it would have made it worse. The fact that it acted the same means that it is the MAF or the connection to it.

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[h_2_o]

DZLbug, that is not true, diesels are completely different than gassers when they deal with maf readings. I just went through this with my tdi beetle. If you look at the diagnosis link i posted disconnecting it is one of the first things to try. If you have a malfunctioning maf and disconnect your turbo works much much better. you will not get full power but default values, check out the threads on tdiclub about running without a maf

Let me google that for you

[DZLBUG]

FT

Originally Posted by h_2_o

DZLbug, that is not true, diesels are completely different than gassers when they deal with maf readings. I just went through this with my tdi beetle. If you look at the diagnosis link i posted disconnecting it is one of the first things to try. If you have a malfunctioning maf and disconnect your turbo works much much better. you will not get full power but default values, check out the threads on tdiclub about running without a maf

Let me google that for you

I've been around the block a few times with this issue as well, and its not quite as simple as you imply. If, for example, he has a connection issue (which is probably the most likely since he just replaced the clutch) unplugging it completely will have the same effect...that is...the ECU will use default values. If the MAF is still functioning, but dirty, it can run at reduced power (similar to it being unplugged)...but stil better than a dead MAF.

Only when the MAF is absolutely dead and giving really bad readings, will disconnecting it improve power. So this "test" is not exactly definitive.


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[h_2_o]

for diagnosis it does help, and a lot. go over to tdiclub.com those guys over there know a lot more than any of us here including you. even being around the block a few times. heck, even rocketchip even uses the maf to induce dyno mode, unplug it and it goes into max fueling

to the OP go read that diagnosis for limp mode, it will help you actually fix your car.

[DZLBUG]

Originally Posted by h_2_o

for diagnosis it does help, and a lot. go over to tdiclub.com those guys over there know a lot more than any of us here including you. even being around the block a few times. heck, even rocketchip even uses the maf to induce dyno mode, unplug it and it goes into max fueling

to the OP go read that diagnosis for limp mode, it will help you actually fix your car.

I never said it didn't help, its just not a definitive test. I've been on TDIclub since 2007 and am "one of those guys" you speak of. Unplugging the MAF does not cause it to go into max fueling, it causes it to go to a preset level that is safe for the engine and turbo.

I wouldn't call the OP's problem "limp mode," that implies something much different. But you are correct, he should be able to find the solution he needs on TDIclub.

[tank]

I am following advice and replacing the maf first. Then, when the temp gets below 110 I will start tracig vacuum lines. After this I will go step by step in the turbo diagnosis link. Thanks to all. I will post the solution when I find it.

[tank]

I replaced the MAF and got boost back. I have not checked it to see if it still goes into limp mode at certain times, but at least I got it back to where I can still have boost while I work through all the steps in diagnosing the deeper issue. It was doing this before I changed the clutch, so I was already planning to do this. Thanks for all the advice.