No power above 2000RPM

I have a 2002 Jetta TDI, that I drive daily 100 miles with about a quarter at 55MPH, and the rest stop and go. The car has 245K on it and gets regular Rotella synthetic oil changes. Recently, I have been experiencing loss of power when accelerating above 2000 RPM. Power just goes flat like its starving for fuel or air. Checked all the usual air snow screen, new air filter, new fuel filter, pulled a vacuum on fuel line from tank looking for bubbles, everything's OK. Check vacuum lines, EGR activator all OK. Just noticed today, that if I run up the RPM (in Neutral standing still), I notice the engine starts to sputter or miss at about 2000RPM. I assume its related to problem. Could I have a exhaust restriction? Any help would be appreciated

Fuel filter? Clogged intake?

Before getting the turbo charger hooked up on my car it did exactly as your describing. It would almost feel like it would start engine braking over 2500 rpm or so. I'm fairly new to working with any diesel or VW tdis but it could be a fairly large boost leak maybe? I think checking the intake would be a good move also. If either of those two cases were to be true I would figure the car would be "rolling coal" a small bit because it would be running more fuel heavy.

Sounds not unlike limp mode. If you turn the key off and back on does power come back.

I'm betting clogged intake or some type of air flow obstruction. I can always tell my intake needs cleaning when power falls flat between 2500 - 3000 rpms.

The "missing" part has me concerned. I'd otherwise say that you should check to see whether you have intake clogging: clogged intakes will make your engine feel very asthmatic.

If the engine is popping ("missing" then it's a timing issue. This could be a bit complicated to pin point. Something like this would tend to throw a code.

Unplug the MAF and see if it runs better. If it does, you need a new MAF.

IndigoBlueWagon said:

Unplug the MAF and see if it runs better. If it does, you need a new MAF.

Click to expand...

Oh, yeah! MAF in the wife's car just completely crapped out, with really no forewarning. The engine got to bucking like crazy. Not a very pleasant thing! Gave her my car to drive and sent her on her way and then drover her car down the road, running like crap, stopped it, unplugged the MAF (while still running) and it INSTANTLY settled down. Went back home and put in a spare, slightly degraded, MAF (and ordered a new one). Suspect it may have been the original MAF: 165k miles (and 15 years old)!

Thanks for all the responses!. I disconnected MAF with no improvement. Turning off the key and restarting does not fix problem. I experience limp mode before when a different senors failed.. The intake clog/ Boost leak are items to check next. I agree with UhOh that the missing/sputtering is a concern, and will also add timing to the list of checks. I first assumed maybe the misses were due to poor fuel/air mixture in weaker (lower compression cylinders). I am currently running a tank with Diesel Klean (sp?) with injector cleaner/pump lubricant in hopes of something happening. I'll keep you posted. Thanks all.
Rudabog

rudabog said:

Thanks for all the responses!. I disconnected MAF with no improvement. Turning off the key and restarting does not fix problem. I experience limp mode before when a different senors failed.. The intake clog/ Boost leak are items to check next. I agree with UhOh that the missing/sputtering is a concern, and will also add timing to the list of checks. I first assumed maybe the misses were due to poor fuel/air mixture in weaker (lower compression cylinders). I am currently running a tank with Diesel Klean (sp?) with injector cleaner/pump lubricant in hopes of something happening. I'll keep you posted. Thanks all.
Rudabog

Click to expand...

Disconnecting the MAF with no improvement = problem with the MAF. Replace.

If you disconnect the MAF the car will go into a mode that assumes some air flow, but not read it. If the MAF is dead disconnecting it will cause the car to run better, but not 100%. If the car doesn't run any different after disconnecting the MAF then move on to the next thing. Replacing the MAF probably won't help.

This happened to me before as well. I pulled that sensor that is behind the passenger headlight and under the washer fluid tank. I cleaned it off with electronic spray cleaner, reinstalled it, and everything went back to normal.

TdiRN said:

This happened to me before as well. I pulled that sensor that is behind the passenger headlight and under the washer fluid tank. I cleaned it off with electronic spray cleaner, reinstalled it, and everything went back to normal.

Click to expand...

The MAP?

Yep that's the one.

Check for stored codes. If the ODBII system is working and there are no codes (unplugging the MAF should have triggered a code, clear that one) it could be something mechanical like clogged cat or DMF failure.

Found the problem

Removed the EGR today and found it the intake 75% blocked. I have pictures in my user album if you like to see the mess. Thanks all for your input.

Found the problem. Intake clogged 75%. See pictures in my user album.

Thanks all.