Audi 1991 Quattro 20V Losing power

Hi All I have a 1991 Quattro 20V and while accelerating I find it loses power at about 4000 rpm and struggles to get to 5000 then kicks in again and its OK.
The fuel pump seems to be ok, no excessive noise
Any ideas !!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Did you service the engine? New filters (air, fuel, oil), oil, ign parts? Possibly weak ign. coil. Any cracked or loose intake boots or vacuum leaks? Did you notice any problems with the air filter like excess dirt or oil? Was any work done recently to the car?
later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
have you adjusted the co or wastgate spring ? have you tried pulling the fault codes? have your local m.o.t station check the co level , www.audicd.pwp.blueyonder.co.uk

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.