Drivability problem

[Penasack, Tim]

Need some help desperately. On my 86 4000 Quattro Rally Car I have a
drivability problem.  The engine bogs down around 2700 rpm until about 3500
rpm where it picks up again.  I have new injectors and injector lines, fuel
filter and lines. Its not the computer because I have swapped in a couple
and I still have the problem.  I'm getting desperate and looking for ideas.

Thanks
-Tim