Zafira hesitation on part throttle - debugslife
The wife's Zafira 2001 1.6 16v goes fine on full throttle. It also idles really well. The problem is when just touching the accelerator pedal after slowing down etc. It is as though the fuel has stopped pumping for a split second. Then it catches up and all is well. Anybody seen anything like this on an Ecotec engine? My first thought is a vaccuum leak but I can't find one.
Zafira hesitation on part throttle - Dynamic Dave
Does it feel like an occasional misfire? If so, My Dad's Astra (51 reg - 1.6 16v engine) had similar problems. Garage ended up changing all the coil packs as they couldn't decipher which one was faulty. Several days later a faulty lamba sensor was also discovered.
Zafira hesitation on part throttle - bimmer-driver
It could be the EGR valve. I had an with an Ecotec engined Corsa that hesitated, and thats what it was diagnose as. According to the Car by Car Breakdown its not uncommon on Vauxhall engines. On mine though the engine management light came on, I don't know if yours has.
Zafira hesitation on part throttle - debugslife
Thanks for that. The first I heard about a problem was the wife telling me the engine light had come on and the car ran really badly with little power. After reading a lot of threads on this forum it became clear that the 'really bad' running was down to the get home mode. I had no idea what to do with it so got a VX garage to get a fault code (no paperclip job on these). The cost was reasonable so it went to them. They said that no fault code came up? Weird, because the engine light just would not go out. They diagnosed a coil pack and we ok'd the fix. After changing it they said it was running ok apart from a slight hesitation (which it has had since we got it) and that he thought it was sticky valves and would put some fuel cleaner in it. I assume that the ok running now was due to clearing the fault code and we are really back where we started, with the hesitation. The EGR valve sounds like a good bet but it is another £150 or so and I am running out of money. Go on, tell me it is an incorrect grade of oil or something cheap!
Zafira hesitation on part throttle - Dynamic Dave
but it is another £150 or so


Source the parts from elsewhere and get an independant garage to fit if you're not mechanically minded. For example, an EGR valve from www.autovaux.co.uk is around £83 (and will more than likely be a genuine Vauxhall part).
Zafira hesitation on part throttle - John S
I had this problem of fault codes not showing on a Vectra. The system seems not to log faults that are either transient, or if the engine is switched off and restarted soon after they appear. The advice I was given was that it needs to be driven with the light on for up to half an hour to ensure it's logged. A friend was given exactly the same advice. Can be a pain if the car's in limp-home mode though!

JS
Zafira hesitation on part throttle - bimmer-driver
On my Corsa, the light usually only came on for a few seconds, but when the fault code was read something was logged. But it probably varies model to model.
Also, a word of advice to original poster- don't bother with all the fuel treatments that claim to clean the engine out. I tried them when mine was playing up, and none of them did the job. Cheaper in the long run to get the EGR valve sorted (if thats what it is)