This may be of some help those who have a hesitation at around 2k rpm or when backed off or very light on the throttle. I have had this problem for a few months now and have finally found the cause after much changing of parts ie ptu, tps , lamba probes, water temp, injector connectors and spark plugs all of which made no differance to the hesitation. What i have found is that the dam hard to get at EGR valve is to blame ( my only problem now is how to completly disable the dam thing while the engine is still in the car) I have temporaly removed the vac line to it and blocked the soliniod outlet, then taken a syringe and pressurised the valve to complety close it then trapping in the pressure. Having done this the hesitation is complety gone only wish i tried it first before buying new parts. Only one problem if the pressure leaks my hesition is back, i have tried to get at the flanges near the throttle bodies but cant undo the bolts while the engine is in the car, i am thinking of drilling the pipes and filling with metal glue any idea any one ?

I heard (but I am not technical so get it confirmed by proper advice) that if you drop the gearbox and do other stuff, you can tilt the engine just forward enough to get at the EGR and replace / gaskets etc. I was told this under a veil of secrecy by the git who ripped me off when he (or his grease monkeys) replaced my knock sensor.

 

Not being technical I have no idea if this answers your question but I hope it helps.

 

If he wanted me to maintain the secrecy, then you shouldn't have been such a lying git Mr Sherwin.

cookie, bob and car tech (peterhead) is good with Z's, he has serviced the one I have for over 3 years.

this sounds a lot like the current fault I have at the moment, the engine is due out again shortly, I may well have to consider doing a bypass. also my knock sensor cable was sheared off leaving it disabled, I have just done a resister bypass temprarily,this has cured a big lack of power generally