DX Won't idle after cambelt change

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:



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

Intermediate Sprocket:



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:



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:



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. 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

Frustrating when you have this happen, but it should be only minor things to sort hopefully!

You've done everything right in general principal it seems, although the cam sprocket mark should be with the cam cover on and the gasket in place so that could make a difference.

Ref your oil leak, although the rubber gaskets are generally better for stopping leaks, given the angle of the engine in your install, you may find you're better off with a cork gasket and a gasket sealer. As you've found the hard way, you can't over-tighten the nuts for the cam cover - 10NM which isn't much more than just hand tight.

Ref the rotor arm, I've only ever timed the slim type which you'd centre to the line on the dizzy body. If that was slightly out I would have excepted you rotating the dizzy would have sorted the problems.

Have you dislodged by chance any vacuum hoses or anything like that? Different engine, but on my old MK2 GTI 16v (KR) I did a cam belt change and had the same problem afterwards. It turned out that I hadn't pushed home a vac hose properly and the vacuum leak was causing the engine to stall at idle.

Also search for timing guides by 'rubjonny' - I can't recall if you'll find them on here but certainly on the MK2 Golf forum. His guides go through all timing steps plus other tuning items to check.

I hope that helps a bit. Let us know how you get on.

Cheers
Andy

I would also suspect a vacuum or air leak, my GTI would tick over very lumply and I spent ages checking, adjusting and changing allsorts in attempts to fix it.

Eventually I let an independent old school VW garage take a look and they found the inlet fanimold was leaking into one cylinder. This was so tiny as not to effect normal running but at tick over was making one cylinder too lean to ignite so it was trying to run on 3 cylinders.

Commiserations with the gasket problem. Not sure if the T25 installation the 'big block' engines had a different cam cover to cope with the engine being on its side?

I fear that now you altered the timing (both cam vs piston and ignition) and fuelling you really someone who knows their way around K-Jet and has a CO meter etc

^^^ Yes good point at the end. If you've got a friendly MOT tester local who will stick it on the analyser for you, you want to be about 1.5% CO, then mixture is about bang-on.

First of thank you all for your replies, really appreciate the support forums like this provide when undertaking basic mechanics like this.

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     

10nm or 87 in/lbs for valve cover, on cork no sealers save for where the cork gasket meats the cam seal, and only 2 drops at that junction.  

My experience is that sealers make the cork gasket slide as you tighten the nuts, and use a zig-zag from center out as you tighten the nut.  Too tight and the casket puckers and oil pools to leak too loose and it leaks…remember Goldilocks?  87in/lbs or 10Nm is just right.

when i do the cambelt I fit it then put a socket on the cam sprocket, turn it slightly clockwise and check the tension on the long run, till I can get about 90 degree twist. then check cam and crank marks still line up, tighten the tensioner.  rotate the engien 360 degrees, recheck all marks. if they are less than a tooth out from each other and tension is still good, then done!

if the mark is out a tooth either way then loosen it, move the cam a tooth in the right direction, re-tighten, rotate, recheck.

Ref gasket sealer, I used one of the non-hardening ones from Haflords. It's Loctight brand but I can't recall the number.

I had a cabby that wouldn't seal right with the cam cover and cork gasket no matter how clean and right everything was. Putting a smear of the sealer on both sides of the gasket sorted it with no issues whatsoever.

It sounds like you have, but do make sure you're using the correct stud type for either cork or the rubber gasket.

Don't put any sealer on the head gasket side if you do end up removing the head, only a new head gasket  

rubjonny said

when i do the cambelt I fit it then put a socket on the cam sprocket, turn it slightly clockwise and check the tension on the long run, till I can get about 90 degree twist. then check cam and crank marks still line up, tighten the tensioner.  rotate the engien 360 degrees, recheck all marks. if they are less than a tooth out from each other and tension is still good, then done!

if the mark is out a tooth either way then loosen it, move the cam a tooth in the right direction, re-tighten, rotate, recheck.

I'll try that tomorrow.

Quick question, do I line the cam sprocket mark up with the head with or without the rocker and gasket on? I did without before but some people say with, that would make a tooths difference I imagine.

I never use the pulley's for timing.
They could of been installed wrong by a PO.

Dimple on the back side of the cam even with the valve cover tin not the rebar.

Crank finger on tranny to 0TDC mark on the Flywheel

Dizzy rotor to the middle of the stamped has in the case of the Diz.

That is the only sure fire method of getting it right the first time.

So I got her fired up today with TDC marks. Runs fine for a minute, but a fast idle then it starts to struggle and revs drop down to stall.

Tried timing light with saucer hose blocked, is it meant to advance when revs are higher still?

What RPM should I have for timing?

Problem is if its idle it stalls, and with revs it seems to advance as the flywheel mark then moves with light on it.

base set is 0tdc.
You have to set it at 6btdc, and that is supposed to happen after the engine is up to temp.

Digi- is different than CIS, and cold is Different than hot.

Digi, hunts for and back for 6tdc after it is cold or hot because of the Knock sensor,,,,,  Puters who needs them.  Some of the better cars I ever owned didn't have them.  Ie: 72 p6 Rover 3500s, and my beloved 67 MG Midget……  Oh, and lest I forget my Rover had a re-designed Buick 215 V8….Strong engine, easy but really really tight to work on. Reliable as all get out….