MOT pass, emissions are TOO good? Cause misfiring/Idle hunt?

  1. Infrequent Poster Joined: May 2009 York-Hull Posts: 222 Saxo VTR MK2
    #1
    Well as i posted before, it failed on emisions. Reason being the cat failed after the persistant misfiring that i cannot sort. Swapped the cat and the manifold as it was cracked, passes with flying colours. But thats my problem, is it too good? The cars hardley producing anything!

    fast idle:
    COlevel = 0.11% PASS-0.2%
    HC level = 0 ppm PASS - 200
    Lambda = 1.00 PASS - 0.97-1.03


    Natural idle:
    COlevel = 0.04% PASS-0.3%

    I sort of guess that this is due to a brand new cat...but surely it should be a little higher, esp natural idle. Its still misfiring (obviously not at the time of test) on cold startups and idle hunting when its lucky enough not to misfire. so could these results help find the cause?

    (For the misfire ive tried: Diagnostics check which returned the result: Random multiple misfire, Ignition misfire on cylinder 1;2 and 3; new coil pack; new spark plugs; cleaned up the ICV and taken the whole inlet manifold off given it a look over and a clean; Taken out the injectors which look fine, no obvious wear/build-up; Also changed oil, oil filter and fuel filter.
  2. Saxperience Forum Bum Joined: Jan 2010 London Posts: 2768
    #2
    Quote:
    Originally Posted by stured View Post
    The cars hardley producing anything!

    I sort of guess that this is due to a brand new cat...but surely it should be a little higher, esp natural idle. Its still misfiring (obviously not at the time of test) on cold startups and idle hunting when its lucky enough not to misfire. so could these results help find the cause?
    Nope, those readings arent too low, my emission readings are even lower on my mk2 vtr!

    Im 100% sure those readings and the missfire isnt related. It also sounds like you have the worst job of testing/replacing any sensor which you assume to be faulty..
  3. Infrequent Poster Joined: May 2010 Wakefield Posts: 220 Furio
    #3
    try replacing the injectors? mine was misfiring and cured this... to test your injectors, take them out and turn your engine over with them out but still plugged in and make sure theyre injecting in sequence etc
  4. Infrequent Poster Joined: May 2009 York-Hull Posts: 222 Saxo VTR MK2
    #4
    Yeh thats what im afraid of. There are so many misfire threads on here and all they ever lead to is 'swap coil pack and plugs, that didnt work' then the thread seems to end. Think we need a misfire FAQ/Guide. Where ALL the symptoms etc are gathered together and the cures . Think il just have to buy a vts engine off of ebay. sounds easier and cheaper. already spent about a grand on this engine....if only i had hindsight!
  5. Infrequent Poster Joined: May 2009 York-Hull Posts: 222 Saxo VTR MK2
    #5
    Quote:
    Originally Posted by pussmunky View Post
    try replacing the injectors? mine was misfiring and cured this... to test your injectors, take them out and turn your engine over with them out but still plugged in and make sure theyre injecting in sequence etc
    I considered this being the problem. But would you think a misfire across 3 cylinders would be injectors? I mean, its unlikly that 3 injectors would fail, right?
  6. Infrequent Poster Joined: May 2010 Wakefield Posts: 220 Furio
    #6
    they might only be failing at times... not constantly. it is also possible that the seals may have started to wear on the bottom, this used to happen with mine so when the engine was warm the seals failed, and at £10 an injector from the scrapyard opposed to around £12 a seal from citroen it was worth just replacing the injectors
  7. Saxperience Forum Bum Joined: Jan 2010 London Posts: 2768
    #7
    If you suspect the injectors - you can swap the good injector (injector no.4 - as suggested by the fault code) with either 1,2 or 3. Then reset the fault codes and get them read again - there will be a pattern if the injectors are at fault. Its a fairly quick process too
  8. Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.
    #8
    Isn`t there anywhere near you that ultrasonically cleans & tests injectors?That may be an option for you.

    Steve.
  9. Infrequent Poster Joined: May 2009 York-Hull Posts: 222 Saxo VTR MK2
    #9
    I got a spare set from a scrapyard, that i can post off to this guy on ebay (was considering demon tuning on ebay, but as stated in the first guys, its not recomended. OR i send them to Mr injector, 8 quid cheaper. Anyone rate any of these guys?

    As i say, i'm not realy 100% its the injectors! Im in the process of getting a new manifold gasket (its blowing on idle, just recently realised thats what the ticking noise is!) so if that doesnt fix it, il be up for some sensors and injectors i guess!! Next step advice is always welcome ha.
  10. Saxperience Addict Joined: Oct 2008 Plymouth, Fiddling - under a two poster ramp Posts: 14064 Audi
    #10
    Injectors make a soft ticking noise.

    If they are silent or sound like a tracktor, they are fucked.

    Do you have a screw driver?
    But the tip of the screw driver ontop of the injector, and the handle end in your ear.

    This will amplify the noise, if any.
    Wham bam, injector man.
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  11. Infrequent Poster Joined: May 2009 York-Hull Posts: 222 Saxo VTR MK2
    #11
    Quote:
    Originally Posted by tonto_VTR View Post
    Injectors make a soft ticking noise.

    If they are silent or sound like a tracktor, they are fucked.

    Do you have a screw driver?
    But the tip of the screw driver ontop of the injector, and the handle end in your ear.

    This will amplify the noise, if any.
    Wham bam, injector man.
    oo this could be useful, il check to see if any are different! The current loud ticking noise is from the front of the engine, deffinatly exhaust, you can feel it! there was a slight improvement to the misfire when i swapped the manifold so i am hopefull .