B4 Passat lots of smoke......lots..

Dad just picked up a 1996 B4 Passat.. Car is great except for alot of smoke off the bottom end.. I seriously leave a huge cloud.. Could this possibly be the 5th injector problem? I'm not up on the B4 like I am with my A4 TDI.. There is decent amount of power, but way to much smoke. It pulls great until 3800 rpm's or so then goes into limp mode. I need to turn the car off/back on to get any boost back...

Any idea's?? Anything I should be looking at? My dad doesn't have a heavy foot, so he hasn't experienced this problem (yet)

There are lots of possibilies, and GoFaster's excellent thread elsewhere in this forum about troubleshooting low-power on the A3/B4 TDI should also be a starting point to diagnose your dad's car because the symptoms seem on the surface to suggest a clogged intake manifold (the test is to log Mass Air Flow in VAG COM as described in GoFaster's procedure).

Other definite possibilities range from the obvious to the obscure... is the engine making boost under load? Is actual MAP following requested MAP? If not, there's probably a boost leak somewhere, a BAD N75 or the small tubes that run between the wastegate, ECU and N75. What fault codes come up on VAG COM? I'll bet "00575 Intake manifold pressure control difference - intermittent" is one...

The 5th injector is also something to look at. Does the car have a BK ECU, or GQ? If it has the latter, the 5th injector is a moot point as the smoke fix has likely already been done.

What's the injection quantity? Spec is 2.2 - 9.0. Lower numbers will of course make more smoke.

Is the injection timing a basic settings at spec?

Are the injectors in good condition?

Was there a tuning box or chip or injectors installed by the previous owner?

Start with these.

You can quickly eliminate the possibility of the 5th injector by unplugging the connector to it (between the airbox and the fuel filter, it's crowded in there) to see if the smoke lessens. Be warned that this may set a code (but it sounds like you've got a few other codes set anyways).

This is unrelated (other than another cause of excessive smoking, except at higher RPMs), but it would also be wise to educate your dad on what to do in case of turbo oil ingestion runaway--not to scare him, but if it ever happens he'll know what to do so as to keep from blowing the engine.

on a 96 passat he may not be able to read the IQ or adjust it. my '96 doesn't allow IQ adjustments via vagcom with the bk ecu...
Thanks
Deo
\x/ hillfolk!