stuttering unless under full boost

[dondarnell]

My 1985 951 sat around for a couple of years, but I have been driving it lately.

It seems that unless the car is under full boost, that it stutters, sometimes quite badly. For example, when driving on the interstate at about 80 mph, the car will cut in and out, or so it seems. When I accellerate, it runs fine.

I thought I had it worked out (thought maybe I had some varnish or water in the fuel), and then it was in the shop for some new control arms, and sat for a week, and now its back.

Any ideas on where to start on this issue?

[Techno Duck]

What is the age / condition of the cap, wires, rotor and plugs? If its only cutting out at part throttle and fine at wide open throttle, test the throttle position switch. There are instructions on how to do so on ClarksGarage. Also a good idea to change the fuel filter if the car has sat for a long time.

[dondarnell]

That makes sense. I will check it out. Many thanks.