when cold, before getting upto 90 deg oil temp the engine hunts continuously, revving from 1000-1500 rpm. when warm (90deg+) its fine, it sits smooth and steady at 1000rpm. occasionally-normally when cold when approaching junctions the revs plummet and momentarily drop real low,but return to 1k straight after,as i say its occasional and not often,and the car never cuts out.the isv microswitch operates as it should. the 5th injector is unplugged, as in the thick of the summer heat it was worse (harder) to start in the mornings..when the car was rr, the guy said there could be a problem with the isv controller as the overrun was sticking open and not closing, so he blanked it off to stop this.? dunno if he blocked the little vacuum tube or the bigger hole into the air intake but the car doesnt cut out every time u lift off like it did before it was rr'd. basically should i try a few new gsf black temp sensors on the head to see if its getting the wrong readings? can always ptfe tape them if they leak like some people say they do? sorry for the long windedness i think its 1 for rj/ben or sum1 else who knows these inside out..