Got any fault codes yet ?
Out of interest you didnt remove the throttle body from the manifold did you ?
A guy I just finished a conversion for had removed his, not sealed it back on and my god was it causing problems, maybe would of helped if he had of mentioned that he had done that ! tried loads of sensors with no luck as well
Chip - do you know if all xe's ran a fuel tank vent valve ? as coem to think about it this guys didnt have one !