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Help please - Fine tuned cam timing but I've screwed up! (TDI BKD)

Discussion in 'A3/S3/Sportback (8P Chassis)' started by ZeeSaffa, May 26, 2012.

  1. ZeeSaffa
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    ZeeSaffa Member

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    Hi all,

    When I bought the car a few months ago I noticed it had a judder when idle.
    So, thanks to a few threads on here I found a potential solution which is to fine tune the cam timing.

    I have the BKD (DOHC) - so after several attempts to adjust the front and rear cam more or less in unison - I managed to sort the idle judder and all was good....

    About 3 days later my car cut out at the lights.
    After turning it over for about 10secs it started. I managed to get it back home with a couple more cut outs.

    When you adjust the rear cam - the value to look at is the [015] Fuel Consumption. You want to keep this to 0.6l/h - which I had done.
    When I got it back home - VCDS showed Fuel Consumption at 1.6l/h!
    So I checked and discovered the rear cam had slipped.... alot.
    It looks like I didn't tighten up the 3 pulley-to-sprocket bolts enough on the rear cam! :banghead:

    I've since set it back to 0.6l/h but it's still in a bad way.

    Symptoms:
    It starts fine when cold.
    Once at full temp it struggles to start.
    Cuts out when pressing the clutch when approaching a stop / roundabout. The needle just keeps falling to 0 RPM with no hesitation.
    It also struggles to pull off sometimes so it's easty to stall.

    Apart from that - once you're going - it feels ok. I think I can sense a slight hesitation now and then - but it might be my imagination.
    VCDS scan isn't showing any faults.

    My local mechanic is going to check it out on Tuesday and make sure all shafts are TDC (back to basics).
    I'm not so sure that's going to be the problem but of course it's worth checking.

    I know this could've been so much worse... but I'm still worried.

    Does anyone have any ideas on what damage could've been done please?
    Last edited: May 26, 2012
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  2. ZeeSaffa
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    ZeeSaffa Member

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    *bump*

    Sorry... Just really hoping for some ideas to think about before my car goes into the garage on Tuesday.

    Any suggestions on possible causes would be great!
    #2
  3. ZeeSaffa
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    ZeeSaffa Member

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    Any help would be massively appreciated please.

    All cams have been set back to TDC (just as a precaution) - it wasn't far off anyway.
    It's still cutting out and struggling to start (coughs / splutters after turning over for about 5-10 seconds) when warm.
    All fine when cold.

    Here's my output from VCDS...

    Can anyone spot anything abnormal?
    (I know that the injection quantity is very varied now... that seems to be happening since the problems began last week - but they were fine a few days before that)

    Wednesday,06,June,2012,17:34:28:20556
    VCDS Version: Release 11.11.3 (x64)
    Data version: 20120401


    Address 01: Engine (03G 906 016 FF)

    17:34:24 Group 001: Injection Quantity
    819 /min Engine Speed (G28)
    9.9 mg/str Injection Quantity
    7.7°KW Injection Duration (specified)
    91.8°C Coolant Temperature (G62)

    17:34:24 Group 002: Idle Speed
    819 /min Engine Speed (G28)
    0.0 % Accel. Pedal Pos. Sensor 1 (G79)
    0 01 0 Operation Status
    91.8°C Coolant Temperature (G62)

    17:34:24 Group 003: Exhaust Gas Recirculation (EGR)
    840 /min Engine Speed (G28)
    285.0 mg/str Exhaust Gas Recirculat. (spec.)
    290.0 mg/str Exhaust Gas Recirculat. (actual)
    44.6 % Exhaust Gas Recirc. Duty Cycle


    17:34:47 Group 004: Pump-Jet Valves
    819 /min Engine Speed (G28)
    0.0 °BTDC Injection Start (specified)
    7.7°KW Injection Duration (specified)
    3.4°KW Torsion Value

    17:34:47 Group 005: Start Conditions (last Engine Start)
    840 /min Engine Speed (G28)
    9.3 mg/str Start Injection Quantity
    48.0 Start Synchronisation
    91.8°C Coolant Temperature (G62)

    17:34:47 Group 006: Cruise Control System (CCS)
    0.0 km/h Vehicle Speed (actual)
    00101100 Pedal Monitoring
    0.0 % Accel. Pedal Pos. Sensor 1 (G79)
    10000001 Switch Monitoring


    17:35:31 Group 007: Temperatures
    80.1°C Fuel Temperature (G81)
    45.9°C Intake Air Temperature (G72)
    91.8°C Coolant Temperature (G62)

    17:35:31 Group 008: Injection Quantity Limitation I (Torque Limitation)
    819 /min Engine Speed (G28)
    0.0 Nm Torque Request (Driver)
    188.0 Nm Torque Limitation
    136.0 Nm Smoke Limitation

    17:35:31 Group 009: Injection Quantity Limitation II (Torque Limitation)
    819 /min Engine Speed (G28)
    -1280.0 Nm Torque Request (Cruise Control)
    410.0 Nm Transmission Limitiation
    136.0 Nm Torque Restriction


    17:36:23 Group 010: Charge Pressure Control
    410.0 mg/str Mass Air Flow (actual)
    989.4 mbar Atmospheric Pressure
    1020.0 mbar Boost Pressure (actual)
    0.0 % Accel. Pedal Pos. Sensor 1 (G79)

    17:36:23 Group 011: Charge Pressure Control
    840 /min Engine Speed (G28)
    1081.2 mbar Boost Pressure (specified)
    1020.0 mbar Boost Pressure (actual)
    76.5 % Charge Pressure Control Duty Cycle

    17:36:23 Group 012: Glow Plugs
    11111111 Glow Status
    0.00 s Pre-Glow Period
    14.06 V Supply Voltage (Terminal 30)
    92.7°C Coolant Temperature (G62)

    17:37:09 Group 013: Idle Stabilization (Injection Quantity Deviation)
    -0.38 mg/str Injection Quantity Deviation Cyl. 1
    1.01 mg/str Injection Quantity Deviation Cyl. 2
    0.71 mg/str Injection Quantity Deviation Cyl. 3
    -1.34 mg/str Injection Quantity Deviation Cyl. 4


    17:37:09 Group 014

    17:37:09 Group 015: Fuel Consumption
    840 /min Engine Speed (G28)
    66.0 Nm Engine Torque
    1.20 l/h Fuel Consumption
    0.0 Nm Torque Request (Driver)

    Thanks!
    #3
  4. max69vk
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    max69vk Member

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    Your torsion value is well out! This is what should be set to 0 degrees, not the injection start. Thats why its a ***** to start when warm, anything over 3 degrees when warm causes 'non-start' situations. Adjust your front cam to hit 0 degrees (or as close as poss) & then adjust the rear to suit.

    Best way is to move the front cam about 1mm & try restarting the engine, dont worry if it doesnt start, youre only doing this to check your moving it in the right direction! When you've work out it you're turning the cam in the correct direction move it in small increments & test it again till you hit 0 degrees & MAKE SURE YOU TIGHTEN THE BOLTS!

    Also only do this on a fully up to temp engine - Dont do it when cold! :)
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  5. ZeeSaffa
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    ZeeSaffa Member

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    Hi Max - thanks for the suggestion!
    I actually started out with my torsion at 3.9kw. The only problem I had at the time was the slight judder when warm.
    Since the cam slip last week I have actually set the torsion back to 0.5kw - but it was still cutting out and running rough when warm.
    On Weds my mechanic set it all back to TDC using the pins which putt he torsion back to 3.4kw - so really it shouldn't have such a big effect if it was running ok at 3.9kw.
    BTW - it actually bounces between 2.9-3.4kw.
    The "Fuel Consumption" [Group 0015] also fluctuate between 0.8 - 1.4 l/h when idling (all components turned off).

    It's going back in tomorrow for the mechanic to look at. He reckons it could be something funny with the crankshaft sensor.
    He's a good guy and I trust him... but I'm thinking that without the proper VCDS he might just be clutching at straws now...
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  6. ZeeSaffa
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    ZeeSaffa Member

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    I've just adjusted the torsion to bang on 0.0kw - but no difference :(
    Fuel Consumption initially was on 0.6l/h (was at full temp) - but after taking it for a 10min drive it's up at 1.6l/h and the injector variation is all over the place.

    I've well & truly #*#*##* it haven't I?!

    Excuse me while I cry :(
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  7. max69vk
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    max69vk Member

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    Very strange, Your mech may be onto something with the crankshaft sensor though. Just for reference here's a shot of my BMN PD170 (I know its not an identical engine) just for reference...

    [​IMG]
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  8. tdi-man
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    tdi-man Active Member

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    if the crankshaft sensor is the one that you have to remove the gearbox to fit this will not stop the warm idle probelm as i have been there and done that
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  9. tdi-man
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    tdi-man Active Member

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    also idle should be 840 rpm think yours is - 819 /min Engine Speed (G28)
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  10. Ash187
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    Ash187 Audi Retrofitter

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  11. ZeeSaffa
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    ZeeSaffa Member

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    Guys thanks very much for taking the time to make some suggestions :)

    The problem is now fixed - and who'd have thought... it appears to have been caused by a contaminated batch of supermarket Diesel!!

    On the morning that it conked out I had just filled up about 5 miles up the road.
    You might be thinking "Why the hell didn't I mention this in my original post?!"
    Well, I was so convinced that it was actually down to the cam timing tuning I had done a few days prior because the "Fuel Consumption" figure was all over the place (FC is the value that changes when adjusting the rear cam) after it conked out and because the bolts in the cam sprocket appeared to be at the end of the oval holes.

    Big thanks to Adam's Autocare (Welwyn Garden City) for his efforts in checking all things cam timing to make sure the problem wasn't down to my stupidity.
    Also to Mark Tempest Auto Centre (Audi specialist) - for diagnosing it quickly (they have had a few cars in this week - all with the same symptoms).

    You know... I only ever use supermarket diesel when I have a voucher... lesson learned.

    BTW - I'm not naming the supermarket - because I want to drive it for a few days to be absolutely certain and I also have to submit a claim. Fingers crossed it goes smoothly...
    #11

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