Help! CGTI TDI CSI NEEDED Please 110 tdi cold startprobs

Discussion in 'Diesel' started by G2T, Feb 26, 2015.

  1. G2T

    G2T Forum Member

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    Hey Guys,

    I need a bit of help getting to the bottom of some issues with a mk1 leon tdi se 110 I`m trying to sort out.

    I`ll try not to ramble too much, it started with a cold starting issue and a flashing coolant light, so it went into a local garage, said it was sorted, no joy, then another garage, they said it was sorted, still no joy. Between them, they`d fitted glow plugs, a glow plug relay, a new battery, a new temp sensor and a new fuel filter, along with damaging the oil feed pipe to the turbo and charging him to replace it. By now it was running a bag of poop and one day I got a call saying they`d only just made it to Tesco and could I have a look, so I grabbed the some tools, the laptop and vagcom and scanned it, it threw up a few codes inc. needle lift sensor, along with some intermittent ones. I cleared them, it started, scanned it again, nothing, so they went home.

    By this time all love for the car was gone and it was replaced.

    I`ve taken it on and started working through things.

    The needle lift issue, was just the plug not fully plugged in, assume a little unintentional present from one of the garages.

    The flashing coolant light was the prongs in the header tank gummed up, I had one off a cupra so I just swapped it, seems to have done the trick.

    Now I have no codes, I`ve driven it up the lane, and its driving well, with no codes returning.

    But despite all the usual parts relating to a cold start issue being changed, it still doesn`t like to start from cold, once run for a short while it`ll re start instantly.

    I`ve checked that there is power to the glow plugs, I did this with a bulb tester, so I don`t know the exact voltage at the glow plugs, but from stone cold today, the relay lit the plugs for a good 20 seconds.

    I removed each glow plug and tested them with 12v, three lit up from the end/tip, and then prob 10-15mm down the probe bit. The 4th lit up from the tip and the right down the probe....

    So, 50a fuse on top of the battery is good, the replaced glow plug relay is working, glow plugs are I think ok.

    I then unplugged the coolant sensor, this makes the ecu fire the plug relay for about 30 seconds, so I started it from stone cold, and it fired up pretty well.

    At this point I`m now not sure if I simply need a new temp sensor, or the fact that with it unplugged, the glow plugs get lit for so much longer and that helped it start ok.......

    Tomorrow I`m going to start it from stone cold with the sensor plugged back in.....

    If anyone can shed any light on this I`d be really grateful.

    So onto the window reg, the osf reg had failed previously, so another family member had got a kit for it and fitted it, but they`d ran out of light and just bunged the door card back on. So I got the doorcard off and it seemed that theyd got the reg working, but simply hadn't attached the glass to the reg. Great, this one was looking easy....
    Wrong!! I bolted the glass in, but the window was very slow going up and down, straining the motor, and at times going back down like it had hit fingers trapped in the window....

    The inner door seal on top of the doorcard was a bit mis shapen where the glass had been wedged, so the car that gave up the header tank donated a tidy one, no difference, tried it without that trim too, no difference, tried another motor, no difference. With the glass out of the way the reg moves nice and freely and sounds ok. I`m going to get some silicon spray tomorrow, but I don`t think that's the root cause, even if it helps a bit....

    The glass doesn`t seem notchy or overly stiff when run by hand, and I`m now a bit stuck.

    I`ll try a fresh tomorrow, but if anyone has any suggestions I`d really appreciate it!!

    Cheers
     
  2. rubjonny

    rubjonny Administrator Staff Member Admin

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    next step i would go thru the various ecu measuring blocks, to make sure the values returned by all your sensors are within a believable range, especially the coolant temp since unplugging it helps! was it a genuine one or pattern?

    just to check, you are switching on the ignition then waiting for the glow plug light to go out before starting the engine? the manual suggests you need to do this, thoughthe wife never does it she just fires the thing up right away (pd150) and it never seems to be an issue apart from sounds a bit rattly for a couple seconds. but then it is a diesel right? :lol:

    ive seen peopel mention to unplug the maf to see if it helps, if so then you may need a new one i guess, worth a look.

    with the regulator try loosenign all the bolts for it, raise the glass fully then wiggle everything about till its kinda 'settled' and glass is nice and square in the frame, then tighten see if thats any help
     
  3. rubjonny

    rubjonny Administrator Staff Member Admin

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    this may help:
    [​IMG]
     
  4. G2T

    G2T Forum Member

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    Hey John,

    A mate suggested checking the temp sensor measuring blocks, but I have never done that before, so will search out a `how to`. Should be interesting, and a learning experience.

    I don`t know if its a genuine one, I will check, but it was a generic garage within 20 metres of a local parts supplier, so I`m guessing not for the moment, would they be diesel/petrol specific, or same for both? I prob have some in 1.8t`s I could swap about.

    Yes I have been letting the coil light go out, my mrs old pd didn't seem to care much if you just cranked it as soon as turning the key either, but for this one yes, no cranking til its gone out.

    Ok, hadn`t considered it could be related, but eliminating every possibility can only help, Ill try that.

    I did consider the I might have clamped the glass without making sure it was positioned right, so I loosened the bolts and raised it up, thinking that it`d find its spot when it got to the top, then helped the glass down and clamped it, but no improvement.

    Thanks very much for the pic and tips, I`ll give them a go shortly.

    Someone else suggested checking the engine timing, although I don`t want to discount it, I don`t know how it`d manifest with these symptoms if it was slightly out, also it had a cambelt 4k ago at a local garage that does do a lot with vag group stuff and it ran spot on for 10mths after that.
     
  5. MUSHY 16V

    MUSHY 16V Moderator Staff Member Moderator

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    If it's a non pd you should be able to check the timing

    You can bring a scope up that being's the timing up that makes it easy to see
     
  6. G2T

    G2T Forum Member

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    Yeah sorry my mistake, it's an asv110 tdi, when I put 110, cos I know it's not a pd, I sort of assume everyone will, oops.

    I've used vag com to check timing was within tolerance, on the Mrs old mk4 after doing the belt on that, is that what you mean? Guessing your on your phone and got auto corrected, the scope bit? I'm a bit confused??
     
  7. rubjonny

    rubjonny Administrator Staff Member Admin

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    with the measuring blocks its easy peasy, open your vagcom, click top left button then click top left again (engine) then click measuring blocks button :)

    scroll thru having a mooch about at what you can find, things like throttle position and anythign with 'temp' in it are of interest. you can monitor other things such as maf grams/second which will help you decide if maf is ok, or if air/boost leaks or whatevs.

    looking at etka temp sensor is same for all models except engine code 'BFQ', but thats a 1.6 so you dont have to worry about that. as i say if you read the coolant temp in the measuring blocks you can see if its ok or not :)

    was a long shot with the glowplug, its not really cold enough i dont think for it to be down to those. unless the pd glows are mega awesome and yours are weak :lol:
     
  8. MUSHY 16V

    MUSHY 16V Moderator Staff Member Moderator

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    Aye bud that was on about and yes I am on the phone
    Would rule the timing out as it is quite common to be out after a timing belt change
     
  9. MUSHY 16V

    MUSHY 16V Moderator Staff Member Moderator

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    Aye the old pd engine's are mega easy to start even when you don't give them time for the glow plugs to heat up
    My old pd starts better than the Leon if you do that
     
  10. G2T

    G2T Forum Member

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    ok so far

    It's had a genuine green (updated?) temp sensor.

    With this and a genuine black one from an 03 leon auq engine, the glow plug light illuminated for apx 3-5 seconds and the relay would click a second later.

    From cold the temp reading were apx 9.0 degrees which seems about right for the ambient temp at the moment.

    It took apx 30 seconds to start with the sensor plugged in.
    Initial timing readings with the revs fluctuating between 880-930 ish were apx 3.7-4.4 degrees btdc.
    After about a minute these were the readings

    Timing
    [​IMG]

    Temps
    [​IMG]

    At this point it'll fire instantly.

    I'm not sure what the values are telling me at the mo, I'm nipping out to get the silicon spray I forgot to get this morning and giving it a chance to cool down, so I can try it from cold with the maf unplugged. I did look at the maf meas. block but forgot the reading and to take a pic, duty cycle at tickover was low though, don't know what that means....if anything
     
    Last edited: Feb 27, 2015
  11. MUSHY 16V

    MUSHY 16V Moderator Staff Member Moderator

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    if you click on the basic settings button i'm sure that brings up the screen with the line for the timing
     
  12. G2T

    G2T Forum Member

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    Thanks for the help so far guys.

    Mushy, I'll try that, when I showed a mate the measuring block screens, he was as confused as me.

    I got the window working, I think there was an issue with the way the new reg repair had been fitted, as I had another complete reg, I fitted that, silicon lubed the rubber guides and it's sorted.

    Still not really any further along with the cold start issue. But it does seem that the issue is glow plug circuit related. If the plugs are lit for a decent amount of time it'll start without issue. But why from cold on Friday would they only be lit for 3-5 seconds with either of the sensors. Vag com seemed to show that they were both reading comparable values. Yet conditions for a good clean start aren't happening. Been advised to try a battery with a bigger cranking amperage.

    Full day at fod on the mountain bikes yesterday, bike clean and repairs to sort today, so will prob look at it again tomorrow afternoon.

    Any more suggestions would be great.

    Cheers
     
  13. Dubnutter Forum Member

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    Might be worth a look at the fuel temp sensor. It makes a difference to cold starting. Its in the fuel pump head, its not difficult to change and not costly.
    Also check to see if fuel is draining back to the tank, this can cause issues, as can the warm up T peice on the fuel filter.
     
  14. G2T

    G2T Forum Member

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    I know this was ages ago, but for anyone finding this, with similar issues, it was timing related. I had to do the belts on my t4 2.5 tdi and needed the tdi timing checker add on for vcds working. Having sorted the van, I used it on the leon, it was waaay out.
     

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