DX Timing Issues after belt change

Discussion in '8-valve' started by bmouthboyo, Jan 6, 2018.

  1. bmouthboyo Forum Member

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    Hi Guys,

    Bit of a long one but best to be thorough and I would really appreciate any help you could give.

    I have a Kjet 1.8 DX engine in my VW T25 Campervan which has been running reasonably well until today.

    I decided to do a cambelt change as I have no idea of its past and when it was last done as well as wanting swapping the cork rocker cover gasket for a rubber one to stop a slight oil leak which I think is compounded by the angle the engine has to be installed into these campervans.

    So I followed the guides on here and all seemed to go well. I noticed the intermediate pulley punch mark was not lined up exactly with the crank pulley line so adjusted this to where it should be and after a nightmare getting all pulleys to stay in position whilst fitting the belt ended up with the following alignement:

    Cam Sprocket:

    [​IMG]

    Lined it up with the top of the head. Not sure if this should have been with gasket on?

    Intermediate Sprocket:

    [​IMG]

    The white mark just above is where it previously was in relation to the crank pulley, looked a tooth out so I adjusted to this position.

    Distributor:

    [​IMG]

    Bit unsure what part of the wide contact should be lined up with the dizzy body notch at TDC. Most guides have the smaller rotor arm which is easier to line up.

    Flywheel Mark:

    [​IMG]

    This was actually slightly to the right of the notch originally but it lined up as in the image above once I had the crank and intermediate marks aligned. I think this is a non GTI flywheel so no 6degree BTDC mark.

    So I started her up and... ran for about a minute, slightly rough then would not idle without high revs. I tried turning the dizzy left and right slightly but it did not stop it from stalling.

    I then tried adjusting the fuel mixture on the metering head whilst turning dizzy left and right but this did not seem to help achieve a steady idle either.

    To make matters worse the rocker cover is now leaking worse than before. I tried tightening the 8 nuts but ended up with 2 threaded, one of which I now need to use a stud extractor as the nut is rotating freely. [emoji20] Not really sure how I can stop this leak as I hoped the newer rubber gaskets would sort the issue.

    At the end of play:
    - Couldn't get it to idle without revs
    - Rocker cover leaking more than before

    So really I am looking for some advice on where to start with getting it to run well again. I have a timing light which I have no experience using as well as no way of seeing the revs. I was hoping to get it idling sound at 0deg TDC then set it up from there.

    Questions:
    1) From my images, does it look like I have the timing marks setup / aligned correctly?
    2) What is the best approach to getting it timed correctly?
    3) What is the order of adjustments? Fuel mixture, dizzy or idle screw?
    4) Any ideas on how I can stop the rocker cover leaking?
    5) I seem to have a wider distributor rotor arm. What part of it should be lined up with the notch?
    6) When lining up the cam sprocket punch mark with the head should I have the gasket fitted or straight with the flat aluminium the gasket sits onto?

    Thanks in advanced for any advice [emoji106]
     
    Last edited: Jan 7, 2018
  2. Jon Olds Forum Junkie

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    Commiserations;
    Two things come to mind:
    Oil leak: There are two types of studs fitted tp the head surface, collared and colarless. When swapping between cork and rubber you have to swap the studs also.
    Timing: Its possible the engine has been timed with the intermediate shaft a tooth out before. I would always set the timing with a timing gun (with an adjustable degree offset wheel, ideally a snap on one, they are great)
    Jon
     
    MUSHY 16V likes this.
  3. bmouthboyo Forum Member

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    So before I give an update here is a video of the running issue I now have after the cambelt change an setting up the timing to TDC:

    https://youtu.be/kPY_68Ahmvc

    The first start was with no added accelerator used. The second start I give it some revs and let it idle naturally from about 1:50.

    Again the car used to run OK before this so I am ruling out any air leaks from the manifold etc for now. I did not get round to adjusting idle screw, distributor or fuel mix today as I was working on my new issue of the leaking rocker cover (hence the smoke at the end).

    It would be great if anyone could advise on where to start adjusting given the rough / cutting out idle in the video.

    Secondary Issue - Leaking Rocker Gasket

    This one has turned from what I thought would be a nice easy upgrade to a rubber gasket to a nightmare.

    In my stupidity, when the rubber gasket was still leaking from the manifold side of my 50 degree leaning engine I kept 'nipping up' the rocker cover nuts. As a consequence 2 of them started rotating freely, and I ended up have to mole grip remove the studs. I have unfortunately now damaged the thread on the head which the studs screw into on 2 of them

    I managed to get the old collar type studs back in, although it had resistance throughout. I will hopefully be able to back to a cork gasket route with possibly some sealant, otherwise this could end up being a head off job and to the machinists to have them helicoiled

    Can anyone recommend a sealant to use? And would I apply it to the head / gasket side, gasket / rocker side or both?

    Whilst researching through past guides on here I noticed I had tightened the cambelt adjuster the wrong way (anti clockwise), so whilst all the covers are off for the rocker I decided to redo the cambelt. I am finding it extremely hard to keep everything aligned once I start tightening the adjuster as it seems to pull the crank clockwise away from the lined up mark. Is there a technique to doing this?

    Thank again for any help
     
  4. dogzila Forum Member

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    If timing marks is OK, try to adjust distributor, when you tightening adjuster intermediate shaft can turn and timing is out of nominal.
     
  5. Jon Olds Forum Junkie

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    To re-iterate, I have made the same mistake recently on an 8V build mixing/matching rocker gaskets. I wouldn't use a sealant and try nad get to the root cause of the problem. I know this sounds easy to say,
    and I am lucky in having lots of parts/spares available, but the problem did get fixed..
    Jon
    Timing light still essential
     
  6. bmouthboyo Forum Member

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    Fortunately I have a timing light and a Gunson CO2 so hope to get these adjusted to reasonable level. It was running fine however before so surprised if I need to adjust fuel mixture.

    I have a tank of 95RON in at the moment, so assume I need TDC for now with timing, no advance?

    Can I check, when aligning the cam sprocket marker, is it level with bare head or rocker cover with gasket on?
     
  7. Rayhoop Paid Member Paid Member

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    Are you sure the sprockets and markings are correct for the engine? In the past I built a frankenstein engine and the cam sprocket had more than one timing mark on it. However in my case we didnt get it running on the incorrect timing mark, but did miraculously avoid piston/valve interference.

    The only other thing I can think of, which you have already mentioned is vacuum leaks. This method is a bit dangerous but helps identify potential vacuum leaks which would result in poor fueling/weak idle: Make sure you don't have any naked flames or electrical contacts sparking... then spray easystart in the vicinity of the inlet pipes, vacuum hoses and manifold. If your revs rise you have a vacuum leak you need to sort.
     
  8. David Hills New Member

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    Hi, I did a timing belt change on my DX engine a week ago. I'm not 100% sure but I think the flywheel mark that you have got aligned is only for when you are using the timing light. I think there is another mark slightly to the right which is the mark that you use for the valve timing, I think there is a small bolt there. My car was running lumpy before I did the change but now runs fine, turned out that the two centre wheels were misaligned by one tooth. I know this because the previous changer put a white Mark where he aligned them to make it easier & they were out of line by one tooth when I had finished. Make sure that if you try my solution, that you turn the engine a few times with a socket/ratchet before you fire her up !!!
     
  9. bmouthboyo Forum Member

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    Does it matter if the intermediate sprocket is slightly out by a tooth or 2, as long as the rotor arm points to the mark on the dizzy body when everything else is at TDC?

    Regarding my flywheel mark, this is installed in a campervan where a JX flywheel is used I think and so it is the only mark. I only show it really as it aligns perfectly when I have the cam sprocket in the correct position relative to the intermediate and so think it is probably the TDC mark. MY intermediate just seems to move out slightly when I tension the cambelt adjuster.

    At present it does run from cold with not a bad idle but then starts to drop revs and eventually stalls.

    I am focusing on any vacuum leaks at the moment and will then return to getting it to keep a steady idle, but just wanted to ask about the intermediate sprocket alignment before adding the covers etc.
     
  10. David Hills New Member

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    Hi, any luck yet ? in my case it made a difference that the intermediate shaft was a tooth out. I think it is eccentuated on the distributor position so you would have to turn the distributor substantially to get it right. If it is wrong, when you are aligning the rotor arm with the mark on the distributor it will be off. I think I would concentrate on this if it was ok before the belt change. If you have a different flywheel, you will have to remove the spark plug on no.1cylinder & get it at tdc by inserting a screwdriver or something to get it right at the top. Have you used a timing light ? Did you remember to disconnect the vacuum pipe from the distributor & block it ? I think it's supposed to fire at about 5 degrees before Tdc. Did you reconnect that pipe ?
    I just bought a Rivage & I have just gone over the whole set up thoroughly on the DX engine. One thing I did have to do was clean the vacuum valve out which made it run smoother. If you try this, use a can of electrical contact cleaner and nothing else. Loads of crap washed out of mine and it made a big difference. ????
     
  11. bmouthboyo Forum Member

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    So bit of an update, today I had her running! I went back over anything I had changed during the cambelt change and remember replacing a Breather rubber that attaches to the top of the rocker cover as mine looked like it was starting to perish a little. I had, what I thought..., was an identical one from a load of DX breather hoses I bought on ebay years ago. It fitted perfect and a nice easy fix I thought.

    Well when I went back and looked closer it seems the replacement was slightly different and did not have a 1 way valve like my setup. It was hard to spot as it is inside the rubber connection on mine but looks like this one I found a pic of on here:

    [​IMG]

    It seems different DX engines had different setups?

    Anyway I think this sorted it, but I had also rechecked timing etc and it fired up and found a semi decent idle. I then hooked up my Gunson analyser and readjusted the fuel mix to 1.8 (think that is ok?) and when engine warmed up I disconnect the vac from dizzy and blocked it, then with timing light tweaked it to TDC mark on flywheel which line up with crank mark and head mark.

    Took it for a drive and seemed to be OK, but still not perfect on idle. Every 8 seconds or so the note of the engine changes slightly on idle then returns to normal.

    Few side thoughts I am now faced with

    1) I want to migrate over to 97 ron to see if 6BTDC helps at all, is it best to let the fuel get low with current TDC timing, then fill it up keeping it same and then on second fill down the line play with timing? Will it run on TDC with 97 octane ok?

    2) I did a dry compression test (admittedly forgetting to open up the throttle however) and I got all 139 ish apart from cylinder 3 that was 170, did it again and same result. Issues?

    3) I do not have a rev meter in my van and would like to ensure the idle is right, and to achieve correct RPM when timing. Can anyone recommend a cheap but accurate engine based RPM meter to use just when tuning?

    4) I was reading around about the vacuum lines etc and just wanted to check I have the correct one connected to the dizzy. I have the bottom hose from this valve going to the dizzy and top one to under the intake manifold. Is this correct?

    [​IMG]
     
  12. David Hills New Member

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    Hi, I think my one from the dizzy goes to the back of the inlet manifold ? When I took off my rocker cover, I thought I would give it a clean and a spruce up/ paint. I took it in the kitchen an did it in the sink with degreaser. One thing I noticed was that the gauze at the oil breather was completely clogged up internally. I had to keep flushing & scrubbing it through. This must have made a difference to the breathing system. Just a thought. Good luck.
     
  13. jamez Forum Member

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    When it goes pear shaped after a belt change it is a sure bet the timings gone astray , id reset it the old school way.

    Remove spark plug on cylinder one and put something down the hole making sure it dose not fall in, a 1/4 extension or something like that then rock the engine over tdc using the crank pulley bolt and watch the extension go up to tdc and down again, a few mm is plenty, after a few movements you'll get a fairly good tdc. Your only trying to see by eye if the tdc is the actual tdc on the flywheel. Once you have set the crank tdc then check the head then the timing. i reckon as mentioned the crank mark you have used is the 6 deg. mark to set the timing with a strobe and not the tdc mark.
     
  14. David Hills New Member

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    I agree with that, the mark you have shown has been painted white which indicates it's probably been used with a timing light, therefore it won't be tdc.
     
  15. Jon Olds Forum Junkie

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    Agree again, basics. I always remove the rocker cover and dizzy cap to see where stuff is pointing at TDC. Usuallly gets the needed result
    Jon
     
  16. bmouthboyo Forum Member

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    Sorry I didnt make it clear, the flywheel is from a JX diesel as this engine is in a camper van. It just so happened to be lined up when I lined the crank mark and camshaft sprocket mark up to the TDC marks, so I knew it must be a TDC mark on the flywheel. I then used a timing light to get it spot on. I have an advance in the timing light so once have 97ron through the system will try 6BTDC.

    Any more info on the dizzy vacuum. Do I have it from the correct point?
     
  17. David Hills New Member

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    Hi again, I think the manifold vacuum pipe goes to the dizzy.
     
  18. bmouthboyo Forum Member

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    So I am currently in the welsh mountains with a pain in the backside idle issue.

    I set co2 to 1.8% and all was well prior to this trip but after some long motor Way driving and really getting engine up to higher temps (130 degrees oil) it struggles to idle when I stop at lights. If I give it a slight bit of accelerator its fine but on its own just about stalls.

    I adjusted idle screw 3 times and each time it raised idle but soon came back later on in drive to Wales from Dorset. Also struggled to start this morning which is rare, needed to keep trying but then was fine.

    Cant test fuel mix but could it need richening ?
     
  19. mk2 nas Paid Member Paid Member

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    I had similar problems last year with my k jet.i havnt used any fancy kit to test gasses just kept tweeking
    The Allen key on the air box by about one eighth of a turn clockwise and did similar adjustment on the idle screw at the same
    Time(throttle body one)adding more idle air it worked for me.but tiny tweets at a time!!
    I think mine is about right it idles 1200 cold and about 900 hot.
    I'm happy with the spark plug colour also I beleive this is about bang on. image.png
    I'm no expert with k jet but what I did worked out.good luck
     

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