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1.8t Starting issues.

Discussion in 'A4/S4 forum(B5 Chassis)' started by Chriscooke, Mar 26, 2012.

  1. Chriscooke
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    Chriscooke Clueless!

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    I recently bought this car with a few issues one of which was a slight starting issue.

    Here is a vid of my issue

    8dc809e8.mp4 - YouTube

    At the end of the vid when the revs rise I blipped the throttle and it roared in to life. the car idles fine also.

    It happens when both warm and cold. I've just swapped out the the cts for a new genuine one which hasn't really helped. The stat needs replacing also but can't see this being related?
    #1
  2. S4_dan
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    S4_dan Fire up the Quattro!

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    Crank sensor maybe?

    Have you had it scanned by VCDS/Cag-Com yet? If not, spend less than £10 and get a kit for your laptop and do it.
    #2
  3. Chriscooke
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    Chriscooke Clueless!

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    I haven't yet no. Is it really that cheap to get the software and cable?
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  4. S4_dan
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    S4_dan Fire up the Quattro!

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    #4
  5. Chriscooke
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    Chriscooke Clueless!

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    Thanks for the link. I've just bought one, all I have to do now is figure out how to use it :D
    #5
  6. Chriscooke
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    Chriscooke Clueless!

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    No error codes found. Well no engine related ones anyway. I'm still thinking its fuel related tbh. Will try changing the plugs as well. Any idea which plugs I need?
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  7. Chriscooke
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    Chriscooke Clueless!

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    Just to bump this with a result. My issue is the battery fitted is too small and not putting out full power at that. When trying to start the car the volts drop to 7v and crashing the ecu.

    New batt should sort it :)
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  8. NineNails
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    NineNails Proud sponsor of the snack food industry

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    I was gonna say do a throttle body alignment. Hope the new batt sorts it
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  9. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    dunno tbh, the voltage drops fairly low on the missus car, so much so that you can hear it struggle to turn over on cold mornings, yet it never has any oddness and always starts on the button.

    Not sure whats up with hers actually, as the battery itself is fairly new, i guess it must be some crappy wiring somewhere!
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  10. Chriscooke
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    Chriscooke Clueless!

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    This is a picture of the current batt which seems too small

    [​IMG]

    Had it on a batt tester today while the mot was being finished which confirmed that it's duff. On a side not I now know that the alternator is in good condition :)
    #10
  11. Arrkon
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    Arrkon Midlands regional Moderator

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    Jeeeeez, that is tiny!!! :ohmy:

    the one in my 1.8T is at least twice the size. Reccomended Minimum spec is 640CCA (cold cranking amps) and 70Ah (AmpHour). think mine weighs about 20KG too, which i doubt that one will....
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  12. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    The one on the avant is the same size! Saloons battery is one notch longer.
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  13. Arrkon
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    Arrkon Midlands regional Moderator

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    The one on my saloon is just small enough to fit the retainer in the very last hole on the battery bracket (with persuasion) lol.

    Does pay to check the drain holes while your there changing it though....
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  14. Chriscooke
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    Chriscooke Clueless!

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    My car still does this. Turns out it wasn't the battery :(

    Anyone got any other ideas? Fuel filter perhaps?
    #14
  15. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    Mine does something similar at random. Sometimes it'll fire right up, other times it does what your video shows.

    I just poke the throttle instinctively now whenever its having an "off" day.

    Interestingly, since the missus car has had its larger MAF and injectors fitted, its started doing it as well. Obviously on hers the MAF calibration on the ECU is out because its not been tuned yet, but maybe that points to a MAF (or other fuelling) issue on yours?

    I wouldnt think its the filter, that would be more of a problem at full load when the demand is the greatest, but it could be gummed up injectors with a poor spray pattern, or ropey spark plugs or similar.
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  16. Chriscooke
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    Chriscooke Clueless!

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    I also prod at the accelerator which helps it start when it's having one of its off moments. I need to swap out the plugs soon also although I don't think the issue lies there tbh.
    #16

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