Help! Vauxhal Vectra 150 SRi Problem

[darren Stricky]

Can anyone help me with this problem. My 2.2 litre vectra sri 51 plate 3 months ago started running crap. It doesn't tick over proper - it's hunting bad, when setting off it tries to die and when travelling under 40 miles per hour it chudders/shakes really bad. Over 40 miles per hour it seems to run fine.
It's been on 2 diagnostic machines both showing no electrical faults or codes displayed it only showed that it was running very rich (It's using a lot more petrol than normal), all air pipes have been checked for leaks, exhaust and sensors have been checked also. It has recently been serviced but that didn't solve the problem. No lights showing up on dash either
If anyone can help me with this problem it would be much appreciated.
Thank you

[burble]

I'd be looking at the Mass Air Flow meter, EGR valve and Lambda sensor. I know you said the sensors have been checked but I'd double check.

[Zak33]

see if your local Vauxhall dealer with do a cheap/free diag on it, cos it's gonna need Tech2 plugging in really.

[garry_uk]

i have the exact same problem mate.i have the exact same car and year.mine has also been on diagnostic machines but no faults show up.

[Paul Boy]

because there are no trouble codes stored, the first thing i would check is the idle speed control valve, remove, clean out and refit, also clean out the housing before re-assemble.