Or one of the three temp senders, I think one feeds the ecu, one the WUR and one the temp gauge. All three are the same (on the gbox end of the head) so if the temp gauge is working OK you could swap the spade connector from that to the other two in turn to see if they give the same temp reading just as a check. There's a cold start injector that feeds into the front end of the inlet manifold on the passenger side, these are electrically activated and can pack up, I know on mine it had been replaced with one from a mk3 I think.
