1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Getting a pain to start

Discussion in 'A4/S4 forum(B5 Chassis)' started by NineNails, Nov 2, 2012.

  1. NineNails
    Offline

    NineNails Proud sponsor of the snack food industry

    Joined:
    Sep 18, 2006
    Messages:
    583
    Likes Received:
    3
    If the cars not been run for 2 or 3 days it's getting a pain to start.
    I will occasionly need to crank it for a good 10 seconds and even then it sometimes only starts and idles very rough untill I switch off and start again (sometimes another 10 sec crank, sometimes not) then all will be fine. It's fine if it's run every day. Like I say, this only seems to happen after it's been stood a while. I checked for codes and there's nothing.
    Any clues at all?
    Thanks :)
    #1
  2. Bradderz_1988
    Offline

    Bradderz_1988 Dont replace it, Upgrade it !!

    Joined:
    Aug 19, 2010
    Messages:
    3,156
    Likes Received:
    100
    Sounds a bit like the immo problem mine did it awhile ago when its was cold never done it since tho.
    #2
  3. NineNails
    Offline

    NineNails Proud sponsor of the snack food industry

    Joined:
    Sep 18, 2006
    Messages:
    583
    Likes Received:
    3
    Nah not immo related. I've had that on another Audi.
    keep the ideas coming though :)
    #3
  4. Arrkon
    Offline

    Arrkon Midlands regional Moderator Regional Rep

    Joined:
    Oct 8, 2010
    Messages:
    1,692
    Likes Received:
    75
    Fuel pump? Fuel could be draining back when left for a prolonged period, which would explain the poor running until key off and restart....
    #4
  5. CHEZ
    Offline

    CHEZ moderately amusing

    Joined:
    Jul 9, 2011
    Messages:
    3,776
    Likes Received:
    531
    glow plugs? as its cold.....................
    *edit* just checked, its not a diesel..................... defo not glowplugs mate lol
    #5
  6. CHEZ
    Offline

    CHEZ moderately amusing

    Joined:
    Jul 9, 2011
    Messages:
    3,776
    Likes Received:
    531
    as its not a derv, i would punt a bet on your MAF then................ as its cold
    #6
  7. OldRedEyes
    Offline

    OldRedEyes Member

    Joined:
    Feb 22, 2010
    Messages:
    442
    Likes Received:
    0
    Temp sensor?
    #7
  8. Ste_Nova
    Offline

    Ste_Nova Active Member

    Joined:
    Apr 20, 2012
    Messages:
    1,225
    Likes Received:
    43
    scanned it for fault codes?
    #8
  9. NineNails
    Offline

    NineNails Proud sponsor of the snack food industry

    Joined:
    Sep 18, 2006
    Messages:
    583
    Likes Received:
    3
    Thanks for the suggestions lads :) but would I not get a fault code if the maf or temp sensor was at fault?. Someone has suggested a leaky injector. They reckon sometimes an injector can constantly drip into a cylinder and cause this after a couple of days. I may try some of that cleaner in the tank. I know it's not had a fuel filter since I've owned it, about 40k now and probably more before i had it. Plugs were changed about 20k ago.
    [Edit]: Yeah Ste, no codes mate
    #9
  10. Ste_Nova
    Offline

    Ste_Nova Active Member

    Joined:
    Apr 20, 2012
    Messages:
    1,225
    Likes Received:
    43
    i had an injector stuck open on my 106, it still started easily but lots of black smoke
    #10
  11. bez101
    Offline

    bez101 Yorkshire & Humber Rep. Regional Rep

    Joined:
    Jul 8, 2008
    Messages:
    8,703
    Likes Received:
    489
    id go for fuel pump draining back or leaky injector
    CTS dont always bring a code up
    #11
  12. Bradderz_1988
    Offline

    Bradderz_1988 Dont replace it, Upgrade it !!

    Joined:
    Aug 19, 2010
    Messages:
    3,156
    Likes Received:
    100
    Crank sensor maybe ???
    #12
  13. shaggy0072
    Offline

    shaggy0072 New Member

    Joined:
    Nov 4, 2012
    Messages:
    2
    Likes Received:
    0
    Hey, I've had this problem myself. 97 2.8 quattro manual was becoming very difficult to start, and even after ignition it would just hack and cough until the excess fuel cleared out of the cylinders... After pulling most of my hair out, I figured if I just unplugged the fuel pump fuse beside the dash (killing the fuel supply.) It would fire after about 2 seconds of starting whilst holding the throttle wide open. When the engine began to smooth out after a few seconds, just plug the fuse back in the holder. This problem for me was intermittent, and it didn't matter if it was cool outside. It would do it at 100F or 20F. It wasn't picky... The fuse trick worked well for me, and the problem has pretty much fixed itself since then... Good luck.
    #13
  14. aragorn
    Online

    aragorn "Stick a V8 in it!" Staff Member Moderator

    Joined:
    Jan 30, 2008
    Messages:
    15,495
    Likes Received:
    299
    stick a new CTS in for a start, they're cheap enough and cause all sorts of funny issues when they're failing.

    MAF is a similar story, but obviously a lot more expensive, however you can try simply unplugging it and seeing how it runs.

    Bear in mind you'll only get fault codes if a signal is out of range. If the CTS has failed and tells the ECU its -20 or +105 when its actually 15c you wont get a fault code, you'll just get an incorrect fuel mixture. The ECU might eventually notice if it stays stuck at -20 forever.

    Same goes with the MAF and various other sensors, if the maf provides readings within the expected range, but that bear no relation to the actual airflow, it'll run like **** but the ECU wont notice or care.

    If its fuel pump related its usually obvious from listening to the prime cycle, the pump sounds very different pumping against pressure than it does pumping free.
    #14
  15. Ste_Nova
    Offline

    Ste_Nova Active Member

    Joined:
    Apr 20, 2012
    Messages:
    1,225
    Likes Received:
    43
    cts is a service part really, my passat had 3 in 10 years
    #15
  16. NineNails
    Offline

    NineNails Proud sponsor of the snack food industry

    Joined:
    Sep 18, 2006
    Messages:
    583
    Likes Received:
    3
    Thanks for all the replies lads :)
    I have had an incorrect fuel mixture fault before but a long time ago and a new stat seemed to sort that. I think I'll try a new cts first then because as said, I know they can cause some random faults.
    I've just scratched by forearms to buggery changing the heater pipe at the back of the head but it's not fixed the leak so will probably have to change the plastic flange pipe thing anyway... Don't look fun :(
    I really need to change the fuel filter too but I just get sod all time!
    Do the injectors pull out easily enough, or does something tend to break? I've started to notice lots of plastic bits & bobs have started to go brittle with age now. I can pick up a set of second hand injectors on ebay cheap enough and maybe send mine away to be cleaned? I think there would be a benefit in doing this anyway at 170k miles.
    #16
  17. aragorn
    Online

    aragorn "Stick a V8 in it!" Staff Member Moderator

    Joined:
    Jan 30, 2008
    Messages:
    15,495
    Likes Received:
    299
    If you want to pay the postage i've got a set of stock injectors in the garage that you can borrow, just return them when your finished.
    #17
  18. NineNails
    Offline

    NineNails Proud sponsor of the snack food industry

    Joined:
    Sep 18, 2006
    Messages:
    583
    Likes Received:
    3
    That's bloody good of you mate, thank you :) I'll bear that in mind. I've got a cts coming so will try that. The thing is, I normally use the car daily so this problem is not really a problem until I take a couple of days off work if you know what I mean. I've not even looked yet on the cost of injector refurb, I've no idea as to how much that would be. Like I said, I guess at 170k it would be a benefit but with xmas and all that... However, I don't want this to get worse as I do need the car daily!
    Is there anything to lead you to believe that if it is an injector it will get worse this side of xmas at all?
    #18
  19. Chriscooke
    Offline

    Chriscooke Clueless!

    Joined:
    Mar 2, 2012
    Messages:
    411
    Likes Received:
    18
    I have a similar issue, in fact I started a thread on here with a video iirc. I've changed the stat and the cts and although it's better I can't help feel its a furling issue. I'm planning on changing the fuel filter when I get time to see if that helps.
    #19

Share This Page