Turbo issues, Need Help
 

After the turbo is spooled up and at about 5-6 RPM's there is a complete loss of power and almost feels like the engine has completely seized and there was a cloud of gray smoke coming out of the tailpipe. but then its fine as soon as i take my foot off the accelerator and upshift(only happens at that rpm range)

Anyone have any ideas of what could be going on?

It didnt start doing this until after I changed out the air filter(dont think this could have anyting to do with it, just giving as much info as possible)

Thanks for any advice u can give me!

Possibly the overboost cutoff kicking in? at what bar?

JP

Check the waste gate hose connections.

Also check the wastegate internals. If the diaphragm is torn, ripped, or split, you will overboost and an electronic switch will kill your fuel at 1.3 bar (quite abruptly). Makes you think you blew your motor (ask me how I know...).

Ditto on checking the wastegate and internals.

The same thing happened to me the first time I drove my 930 & got on the boost. It shut down VIOLENTLY at 0.8bar, I thought I broke something...turns out the WG was rusted shut. Purchased another WG and checked it out before installing.

The over boost switch (located behind the intercooler on a 79?) when activated, will cut the fuel pump and this is the violent shut-down you feel. It also could be the rotor governor in your distributor, but not likely, as those springs rarely fail.