Hi i'm new here. I have owned my 52 plate ST170 for 8 months and for most of that time it has had an annoying stutter. This happens mainly between 30-40mph in 3rd or 4th gear. The car dosent run as smooth as id like but when you go through the revs its fine and revs freely.

The stutter isnt like a miss fire. Its more like the engine holds back on and off for a couple of seconds. There are no fault codes but its been plugged into a snap-on diagnostic machine which shows the e-vac isnt working propely but i have already changed this and checked the vacume and other pipes coming from that and all seems fine.

Hope someone can help as my patience is really running out of patience and would like to sort it before i sell it in the next couple of weeks.

Adam