Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Nigels]

Hello all, sorry I haven't posted since I joined - I've been busy looking for work! Well the Omega has just failed it's MOT on emissions (excessive carbon monoxide content), on the advisory it stated the engine appears to have a missfire and it did seem quite rough when driving back home and was definitley down on power. Did the paperclip test - no codes. Checked all the plugs - 1, 3 and 5 had very small amounts of oil in them so I suspect the gasket is starting to fail. Put new plugs in and cleaned the HT boots as well - no cracking or any signs of damage. Cranked her over but she's still running rough. Checked for spark on all the leads and they're fine. The Dis pack was changed just before I bought it (less than 6 months ago), but I checked just to make sure - it's clean, dry, no signs of any damage and looks brand new (plus if it was failing I wouldn't expect see spark on all the HT leads). So now I'm at a bit of loss, any ideas on what else to check?

Nigel

[kevinp58]

Hi do a compression test and see if anything comes up

[Abiton]

See if there are any members local to you (with same engine) who might be prepared to test-swap MAFs with you and see if the problem stays or goes?

Try blanking EGR temporarily or permanently if not already done?

[The Red Baron]

See if there are any members local to you (with same engine) who might be prepared to test-swap MAFs with you and see if the problem stays or goes?

Try blanking EGR temporarily or permanently if not already done?

thats what i was thinking too tbh.

[Marks DTM Calib]

As always start with the basics.

Measure the lead resistances (I suspect the method used for checking for spark is probably not good enough unless you have a specific test plug)

Check for air leaks paying particular attention to the breathers, servo vac hose etc.

Possibly blank the EGR off (or tap it although they run VERY rough when these are stuck open a reasonable amount)

Clean breathers and throttle body plus idle valve.

Check plugs are torqued down ok.

[Nigels]

Thanks for all the responses, I did the spark test again in the dark and this time I noticed that number 1 lead was considerably dimmer than the rest. I took the drivers side off ( 1, 3, 5) intending to check the resistance, but once I'd got them off the car I found the number 1 lead was loose inside the rubber boot that connects to the spark plug - it wouldn't come all the way out but definitely wasn't connected properly, hence the missfire and rough running. Just put a new set of leads on from Euro Car Parts (only £35 delivered) and everything seems to be running smooth again. Just a quick question regarding the EGR - is it worth blanking and how does it effect emmissions for the MOT ?

Regards, Nigel