iv got a 2wd saff running around 350-380bhp it has air to air injectors,light blue fuel injectors.it rescently devoloped a small proble,when its been for a blast and gets bit warmer then usual it starts running lumpy and doesnt boost properly.when it cools down its ok again.the other day i floored it and it would only peak at 20 psi instead of 30.it held back as if i lost power.then it back fired hard and all the power came back for a while.iv changed the following:group a coil motorsport leads motorsport oil.it doesnt do alot of miles but im stumped.can anyone help please?want it sorted before ford fair if possible