My son has just got a non running RST S1, it had a blown head gasket, and a new recon head fitted, as well as a new Turbo, I assume 8mm lift in a turbo shaft is excessive

When he got the car it just about ran, now, when it turns over first time if fires a couple of times then dies, and will not fire again unless you leave the car for a couple of hours, Im thinking metering unit, it was full of mayo, crack the feed to the front of the unit and there is plenty of pressure, but virtually nothing if you crack an injector pipe open, If I push the diaphram?? down when the ignition is switched on it makes no difference, no noises, nuffink any suggestions??
Ian