99 TDI Jetta- engine quits pulling about 2600 rpm

Have been working on this too long, Need Help!! Car pulls good till 2600- 2800 then falls off. Boost pres.falls below 1500. It gets as high as 2386. Mass air flow falls off same time-680 to 450. I seen air in fuel line, but has since quit for some reason!! It acts like it is running out of fuel OR turbo problem? Any Ideas? Help, please gt

Assuming you are speaking about an A4... log MAP specified and actual, MAF specified and actual, 100% throttle 2000-5000 in 3rd gear, repeat 3 times. Plot the data in Excel and you will know what is going on. I can speak to MAF failures as I have had 2 of them on two different cars, MAF actual will jump to maybe 800 and then slowly decline to 500;this is a no CEL MAF failure.

Let us know how this turns out.

yeah listen to jayd. I shouldn't post before my first beer of the night /images/graemlins/grin.gif

Sounds like a MAF. Unplug and see if power improves. If so, replace MAF.

I have a 2.0L maf, I know people was using them. I was going to try it in the morning. Thanks for the imput. gt