My car has developed a problem that three mechanics including Vx have been unable to identify the cause. The main problem is that no fault code or EML light has been activated.
The car is a Vectra sri '05 2.2 direct engine type z22se (twin exhaust model).
It struggles to start especially in the morning when external temperature is cold. The engine will fire but will not hold idle and will slowly die (almost like insuifficeint fuel supply or difficulty sparking is best way to describe). It has be known to idle at 200rpm which i thought was impossible.
Once the engine has come to life then driving is frustrating. The symptons are;
Revs must be above 1200rpm when pulling away otherwise the engine will stall.
When driving and placing the engine under load there is no throttle response or performance between 1000 and 3500rpm in all gears but worse in 4th and 5th. The car will slowly speed up and when at 3500 then the car will accelerate but still with restricted performance.
When cruising in 1st or 2nd gear the engine feels like it is both restricted and surging (not sure how to explain this).
The main things that have been checked out include by three garages and all chacked out ok;
MAF sensor
Fuel pressure regulator
HP fuel pump
Fuel lines
Exhaust removed to test for blockage
Lamda sensors
Spark plugs
Cylinder compression
Timing chain - appears to be ok
Just had a new fuel filter fitted and also put a fuel cleaning additive in with full tank of premium fuel in case the last tank of fuel was dodgy.
Looking on the internet and speaking to people, the other potential causes include;
Faulty crank shaft sensor
ECT senor
EGR valve - suggestion to either remove and clean or spray wynns petrol egr cleaner into airbox
Coil Pack
Pre-cat (not sure if there is one)
Currently pulling hair out as I really need the car so any suggestions needed.
Regards
Steve