lol i was about to post that mine is having the exact same problem, but i'm pretty sure it's the same car - i bought from Finny yesterday

We also replaced the amal valve with a new one today but no joy. So we tried by-passing it instead and then when it mis-fired / jutterd it would suddenly rev on past 4.5k and pull on very strongly to the limiter, we set the boost to 22 psi and it runs fine before and after 4.5k revs but it seems to be when it comes on full boost it misses / boost cuts in and out. We turned the boost right back down and reconnected the amal valve.

We re-checked everything again today from plugs and leads through to coil etc and no joy, checked all the sensors we could think off too.

If the boost is set to around 8 psi it pulls smoothly with absolutely no missing right throughout the rev range but alas i'd hoped stage 3 would see me into at least double figure psi


Terry