I have a 2002 Vauxhall Zafira 1.8 Club 16v engine type Z18XE. I have had it for 9 years, it has been serviced regularly & been reliable up to now. It has done 79,000 miles.
A week or so ago it started to run roughly. The first thing I noticed was that when you start it up, it revs more than normal for the first few seconds before falling back to ticking over. If you then drive it from cold it struggles to move, you have to drop the clutch & try to rev it a bit to get it going. Once it is warmed up it is a bit better but still very bad. If you try to accelerate more than very gently you normally lose all power. You seem to get the best acceleration (but very little) by using low revs & moving through the gears but this only works on the flat or down hill. Getting above about 40mph is a challenge.
I took it to a local garage who replace the fuel filter, removed throttle housing & cleaned breather pipes, tried new spark plugs, tried new lambda probe. They thought that air mass meter was giving wrong information to the ECU so they tried a new air mass meter (said did not fully fit (mechanically I assume they meant) the new one but connected it in electronically) but it did not make any difference. They said that it was running very lean because there was virtually no CO2 in exhaust emissions and usually old Zafiras have lots of C02. I have just looked up the last MOT & the Fast Idle Test reading was 0.011%, the Natural Idle Test was 0.000%, so seems my car has low C02? They said next thing to try was repairing ECU.
This garage was recommended by a friend but I have not used them before. What they said made sense but they are not Vauxhall/Zafira experts.
There is no warning light & garage said that there was no error code.
Repairing/replacing ECU is quite expensive given car is old so I don't want to do this unless I am confident that it will fix things. I am looking for advice from someone who has experience of similar Zafira faults & can advise whether an ECU repair is the next thing to do & if so where is recommended for this, or if other things should be checked before resorting to an ECU repair.
Removing ECU sounds straight forward so hopefully I could do this & send it away.