misfire

[buddyboy]

my astra 1.6 w reg is juddering on acceleration. garage cant find anything wrong but acknowledge there is a fault. spark plugs were new in october and are fine

[Ward-Minter]

Could be the oxygen sensor. I know to save money some of the Vauxhalls didn't link them to the Engine Management System so no light came on. Check under the chassis. There should be a cylinder a bit smaller than a  spark plug sticking out of the cat converter. Give it a wiggle, if its loose its probably knackered.

[stretchyskin]

commonly called a lamder sensor

[Lecky]

Hello all

This is a long post, so settle down with a Cuppa and I hope it may help someone, someday.

Temp showed Normal

No Lights, temp/oil/ECU. Fuel consumption also seemed a bit heavy, but this was my first Vauxhall....

Investigation starts:

1. Breathers - All ok, clear.
2. Intake air leaks. - none
3. Air Filter - Ahhhh. BLACK.... changed (�8), test drive. Same dodgy idle and acceleration
4. OK, I can do this. Search the net for help. Found this forum and started reading.
5. No point in reading ECU as no light seen. (error)
6. Clean Idle control stepper motor. - Idle now stable, no more stalls, but still hisitation on acceleration. We go on...
7. Disconnected O2 sensor - Ahhh... that's better, idle ok and pulls better, replace with new O2 sensor (�39)
8. Drove well for about 10 miles, then back came the symptoms.
9. Check and changed Plugs (�18) - still the same
10. Cleaned all fuel areas - Thorough to the letter - still the same.
11. Back to the forum - OK, EGR perhaps? Cleaned - same.. Do I buy a new one? Damn, �70... oh well, got the car cheap so go for it. - Same symptoms again.
12. Read that it could be the Temperature sensor - OK, �11, in for a penny...(lots of them) - result... nope, same hesitation...
13. Rechecked all of the above. I am now a master at this.... or am I?
14. OK, forum tell me it could be the MAP sensor. This time none in stock at local Vaux dealer, so down to scrappy... Yep.. �8.81 (bargain) But, still no change.
15. Do an ECU reset, lets see if it needs it. Memory cleared, not that I had checked it. (error)
16. So, what more can I do? The only improvement was the stepper motor clean which made the idle 100%