Loss of power...turn car off on fine again

Hey guys I’m having some issues with my 2002 ALH. I haven’t had it for more than a month and already replaced the shifter cable and now I’m having power issues. It doesn’t always act funny. When I say act funny it’s like the turbo isn’t working, it still runs but semi slow. The guy I bought it from deleted the EGR and he had taken off the valve that’s on the outside of the manifold. I turn off the car and back on and it’s fine again. I’m not trying to spend thousands of dollars on what seems to be something easy as a sensor or valve. I am no mechanic so please anything will help

My daughter just had a similar issue on her 03 Jetta. I checked everything from vacuum hoses to boost pipes etc. It turned out to be her MAF sensor wasn’t getting a good connection at the plug. Cleaned it up, sprayed it with some electrical spray and it’s been working fine for the past couple of weeks.

Classic "limp mode" when power returns after a restart. Many causes, often vacuum leak related, MAF issues, stuck turbo vanes/actuator, etc. Do some searches.

In particular, member Canadian Grizzly has a great step-by-step HOW-TO for diagnosing all the various causes of limp mode:

http://forums.tdiclub.com/showthread.php?t=179589

Do you have any way to scan it for a code? It could be over-boost or under-boost. From my experiences, over-boost is usually caused by sticky vanes in the turbo. This can be "fixed" by disconnecting the down pipe and spraying a carbon solvent (oven cleaner, Seafoam, etc) and working the actuator arm until its smooth. This is not a permanent fix but is a cheap/quick way to get your car going. Symptoms are boost spikes over 20 psi (sometimes feels like you have more power than normal while accelerating followed by limp mode).

Under-boost (P1556 Code) on my 03 was caused by a vacuum leak. i had a split vac line going to the ASV valve, but it could be anywhere in the system. Symptoms were no power till about 2200 rpm then the turbo would build boost. if it stayed around 2000 at high load, it would got into limp.

I've never messed with an MAF but you can test it by unplugging with the car off, then start and run. if you have more power and no limp with it unplugged then you MAF needs cleaned or replaced.

The first two resolutions are cheap and dont take much time. In a few hours and $20 you could have your turbo cleaned and vac lines fixed if you already have a mity vac. Probably wouldnt hurt it clean the turbo and check vac lines anyway. MAF is more expensive.

As said, look over your vacuum lines for leaks, inspect the hardline from the pump to the brake booster.

Also get a 14mm wrench and move the turbo actuator, see if it moves freely


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I had the same problem when i got my jetta. I replaced all the vac lines, removed and cleaned my turbo, intake manifold and maf sensor. Also drained some oil in the intercooler. Never had any issues since

Diagnosis-
our thread
myturbodiesel thread
Or for thousands you can buy another car with similar issues.
I might suggest reading the TDI FAQ (a note at the top says it's out of date, but that's not exactly true).
I've had limp mode 3 times, first was rusted frozen actuator, 2nd was a damaged wire (#3) from the IP to the ECU, this was an outlier. 3rd time is on my new-to-me '03 NB, does it so rarely I've been unable to diagnose.