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Topic: 1991 1.6 EZ petrol 8 valve timing marks discrepancy  (Read 578 times) previous topic - next topic

1991 1.6 EZ petrol 8 valve timing marks discrepancy

Hi all I need a bit of advice/help with my timing, I just want to clarify which of the marks I have are the timing marks I should be using, and if the timing is currently not correct and this is ultimately causing my idling issues ( continue reading for further information). My car has always idled a bit erratically, it pulses a little and I don't think it's meant to, or not as much as it does, but  this is my first mrk 2 and have not got anything to compare it to. Plus unless I rev it slightly when cranking it, it will either cut out straight away or run for a few minutes then cut out. When driving if I push the manual choke all the way in, then when I go to do a hill start with a load ie a few passengers, it will run really lumpy and rough, and even cut out. I have found if the choke is out so the car is running at 1500rpm at all times, I tend to not have any issues. Now from what I have read so far online this could be caused by a timing issue,

Someone before I owned the car has put an aftermarket carburettor on it, ( I don't know what brand, I don't know how you tell), I have not owned a car where I've swapped out the standard carburettor for a different one so a bit out of my depth here. The carb that has been fitted comes with it's own filter that sits directly on top of the carburettor, as the shape of the whole is oval but the air box has a standard circular whole, so things have been made to fit, I don't know if this is the cause of the problem or simply just adjusting the fuel jets in the carburettor. In case your wondering I have added this information for transparency on what might be the route cause of the issue. 

So back to the timing, I was looking at what the timing marks are meant to be etc, I have a Haynes manual and through that but hasn't seemed to be much help to be honest. It seems most people align there cam with a mark on the back of the cam with the top of the head where it meets the rocker cover. However just to make my life even more difficult, my timing mark for the cam is different. I have a plastic back plate situated between the camshaft and engine, and there is an arrow on the plastic back plate with the letters ot next to it, on the camshaft pulley I have a mark that also has the same letters next to, now logic might dictate this is the timing mark. From what I have read online I think it is. However there is a second mark on the camshaft which is just a dot, similair looking to the one on the intermediate pulley which is what turns the distributor.

Now comes the fun part, there is meant to be an engraved small vertical line in the auxiliary crankshaft pully which also aligns with a dot that I mentioned above, on the intermediate shaft pulley. I can not see this line anywhere, I have taken the pulley of spun it round multiple times in my hand looking for one, it just isn't there. There is still some paint which is peeling off in various areas around the pulley, I don't know if it is original paint, or if someone has repainted it, and the paint is cover the vertical line.

I have been able to locate the marks on the distributor with the cap off, which is nice and simple.

I have left the most confusing part till last, the flywheel! I have removed the bung from the gearbox, but haven't been able to remove the outer plastic part which is screwed into the gearbox, I will have to invest in a giant allen key if it becomes apparent that this needs to be removed. On the flywheel I have several different notches, and engravings you name I seem to have them all. I have already read online and most seem to use just one, and again the haynes manual isn't great at providing information for this. So I have a diamond engraved and then 2 separate engraved dots, which are directly next to each other, but you see one then turn it a bit more and see the second, or at least it looks like there is 2, but it is oily on this part of the flywheel so a little hard to make out. Additionally to this I have what some may refer to as a VW timing lug which is used with a specialist vw tool, I believe I actually have two of these as well. I was able to locate this guide from another forum: http://www.cabby-info.com/Files/AdjustingTheTiming.pdf go to page 2 in the pdf I seem to be able to see both the step 2 image and the notes image.

Now from what I have gathered from some limited research most people use the engraved dot located next to the engraved shape, I think it looks a bit like a diamond or an arrow, but if I line up the ot mark on the camshaft pulley to the mark on the plastic backing plate, this also means the distributor is aligned, but when I check the flywheel I see the timing lug, and not the engraved dot and diamond shape. In order for me to see those, the camshaft pulley mark is 180° and so is the distributor.

I do believe it has had a clutch in it's time, I know the flywheel usually doesn't come off for this procedure, I don't know if someone has removed it for some other reason, I do have a record of a timing belt replacement as well, so I don't know if it was incorrectly aligned previously. On some of the flywheel marks though they have been tipexed for some reason.

I have changed the belt today, and just used the ot mark as it seems like it is what was used in the past and I think it is the correct mark, I didn't break my engine, and it runs how it did before I changed the belt, I just ultimately want to resolve this issue, and get to the bottom of these marks on the flywheel and which one I am meant to be using.

If anyone could help clarify what marks I should actually be using, whether this is causing my idling and slight erratic idling etc issues, as I have read that it can cause issues with idling etc if the timing isn't set correctly.

Here is a picture that has the timing marks which I can also see on the flywheel, when the cam is timed, I believe I am seeing the right most timing lug, and in order to see the TDC mark, the cam needs to be 180° out, I think I can also see to marks which both look like the TDC mark, but it is oily on that part of the flywheel, so not easy to tell. Ultimately I want to know if the flywheel being out would cause me my idling and starting issues, and whether the flywheel being out is something that needs to be rectified.



Carburettor photos:
        

          

Re: 1991 1.6 EV petrol 8 valve timing marks discrepancy

Reply #1 –
I cant answer your questions about the timing but hopefully someone else will.  However, I can do the Carb bit.  The chances are someone has fitted a weber 32/34 DMTL twin choke carb.  Have a look on the side of the carb for "weber".  Also you could post a photo of the carb.  There is a fitting kit for this, and it allows you to fit the original air filter housing.  You can buy all the parts from webcon.  You really need the original air filter for the carb, so you get the hot air feed from the exhaust.  With a weber you will need to pump the throttle a wee bit when starting the car from cold, with the choke fully out, then you should push the choke in to give you 1200rpm, and keep it there until the engine is fully warmed up, and which point push it all the way in.  If it is struggling when warm, and gives better performance when you pull the choke out this suggests that the carb is running too lean and you need to make it richer.  You can adjust the mixture screw, its on the left hand side of the carb as you look at the engine, by turning it  anti clockwise to richen it.  Try half a turn of the screw at a time.  The idle is adjusted by the throttle stop.  There are various images and pdfs on line for this carb just do a google search, so you can find out where the mixture screw is.

Re: 1991 1.6 EV petrol 8 valve timing marks discrepancy

Reply #2 –
Thanks for this reply, I will see if it says anything on the side of the carb. In regards to the starting I don't start it with the choke fully out, as it also seems to reluctant to start this way, for some I have found with the way it currently is, the best solution is to crank it and with my foot on the accelerator, and when it starts to adjust the choke accordingly to get it the 1500rmp sweet spot, and then if I just drive for no more than 1 minute and come to a stop, I would then need to make some minor adjustments to the choke again, potentially pushing it in ever so slightly as it tends to go up to 2000rpm.

Trying to get it to 1500rpm on the choke does take a few goes as it seems to be very sensitive around this area, and will either start dropping suddenly or go.straight back up to 2000rpm So gently tapping it with my hand, or as I push it grab the shaft between my thumb and index finger, to try and mitigate for any over adjustments I might make, as it is a bit stiff to push in this spot especially when trying to make millimetre adjustments.

I have found when it got up to temperature, if I was to push the choke all the way in, and go up a hill with a load, it would either be really lumpy and rough or go to cut out, maybe it wasn't hot enough and I need to give it more time.

At the minute I am doing quite a lot of long distance motor way journeys, until my other car is drivable, so I wouldn't really notice any lack of performance, but I do leave the choke at 1500 rpm on idle anyways.

Just a question of curiosity, why do these with a Webber carburettor, prefer to idle at 1200 rpm, where most cars usually idle at 800 - 900rpm approximately?

A follow up question from that, is would it be possible to adjust the mixture screw such as, that it would run fine at idle at 800 - 900 rpm?

Any advice much appreciated!

Re: 1991 1.6 EV petrol 8 valve timing marks discrepancy

Reply #3 –
Yes.  A weber should idle at 800-850rpm.  The fact that you have to pull out the choke when its hot suggests to me that its too lean, i.e. not rich enough.  Once you adjust the mixture, it should run much better without the choke out.  Making small adjustment to the choke when its warming up is normal.  Its what we all used to do before automatic chokes were invented. Its worth making a mental note of where the temperature gauge sits when the engine it up to tempterature, ie when the fan cuts in, that way you will know the point at which you should have the choke fully in.  Having said that, once you have fixed the mixture, you will know, because it will fine fine without the choke. 
According the weber instructions this is how you set the mixture.
Get the engine up to full temperature.  Unscrew the mixture screw anticlockwise and the revs should increase.  When the revs hit there maximium point (this may take a little backwards and forwards to establish that).  Then turn the screw back in clockwise one half turn.  This should reduce the emissions without effecting performance.  Once you have done this, adjust the idle, via the throttle stop until you get an idle of 850rpm.  You can buy the instructions for the carb from Web con.  Its a pdf download.  It also has an exploded diagram so you can see all the parts you are missing.  There is also a utube video on how to fit the weber to a mk1 Golf, which is basically the same as fitting it to a mk2.  By the way Webcon are very helpful, and they will be happy to sell you individual parts.  I bought some parts to convert a weber from an automatic to a manual transmition
https://youtu.be/sL7Nk8LiG2A

Re: 1991 1.6 EZ petrol 8 valve timing marks discrepancy

Reply #5 –
Sorry typo my bad, it's an EZ, glad someone is paying attention, I have corrected the typo now.

Re: 1991 1.6 EZ petrol 8 valve timing marks discrepancy

Reply #6 –
I just checked my carburettor and it's a ramair carburettor, I don't know if that is good or bad. It has 2 separate same sized holes going downwards, so I'm guessing that means it's a twin carburettor.

Re: 1991 1.6 EZ petrol 8 valve timing marks discrepancy

Reply #7 –
Ramair make foam air filters.  I doubt they make carburettors.  Under the air filter it should have a weber.  Take a photo of it from various sides and post it and I'll be able to confirm it.  It sounds like a twin choke carb which has a primary and a secondary.

Re: 1991 1.6 EZ petrol 8 valve timing marks discrepancy

Reply #8 –
I'll add some photos, I did have a look around the carburettor, didn't see any name engraved, doesn't seem like there's is room for it with all the gubbins of the carburettor anyway. I did manage to left the front of the filter up, and it did have ramair engraved on a piece of metal, but perhaps this just is part of the filter fitting kit.

Re: 1991 1.6 EZ petrol 8 valve timing marks discrepancy

Reply #9 –
II think it is a weber carburettor, I had another look tonight, clearly wasn't looking properly previously! I have added some photos anyway for clarity.

Re: 1991 1.6 EZ petrol 8 valve timing marks discrepancy

Reply #10 –
Yup, it’s a Weber. This is the mixture screw

https://flic.kr/p/2oCJDMz

Re: 1991 1.6 EZ petrol 8 valve timing marks discrepancy

Reply #11 –
Hi all so just an update on where I'm at, I got a second opinion of someone who knows more about this stuff than me. He recently has done a clutch on a mrk 2 albeit a cabriolet, which might be a slightly different setup but he said that the flywheel can only go on in the one place, meaning that the flywheel timing mark must be in the correct place.

Once number one plug was removed and the flywheel was set to tdc, and checked that number one cylinder was also at tdc, we could determine that, for whatever reason someone had fitted the belt with the front of the engine being roughly 180° out.

I was able to remove the bung in the top of the gearbox without letting it all fall down inside, I managed to hacksaw of a chunk of the plastic from one end, then used a long but small flat bladed screwdriver, and a hammer and gently tapped the screwdriver around the bung, to try and break the main carcase away from the thread part of the plastic, so I could then pull it out and deal with the remainder. By doing this the whole thing just suddenly came loose and I managed to remove it.

As there is no engraved timing mark on the auxiliary crankshaft pulley, I timed the front of the engine up, and used tipex to mark where it should be. Then I timed up the flywheel accordingly, removed the belt, turned the crankshaft and camshaft back to the correct position, removed the rocker cover to confirm and refitted the belt, and the rocker cover.

Once the belt was back on I then had to adjust the timing on the distributor using a strobe light in the whole in the top of the gearbox, but before doing this I adjusted the idle speed, which is the small screw with the spring on it, located to the left of where the throttle cable (covered in red insulation tape is), (see pic 5 of carburettor), I managed to get the idle down to 850rpm, adjusted the timing by rotating the distributor until I could see the diamond pointer in the top of the gearbox. Now seems to be able to run at lower rpm then before. The idle speed might need tweaking a bit as seems to run a bit high.

I do have one question though, so from the research I have done on some models (I think the later ones, but I could be wrong!), the timing mark on the camshaft is the OT mark which aligns with the arrow on the plastic back cover. However there is also a dot on the camshaft pulley as well, and to confuse matters even more there is an OT mark as well as a dot on the pulley for the distributor or what some may refer to as the intermediate shaft. I wanted to know if anyone could tell me what the OT mark means, or what OT stands for, I'm guessing something in German, I also want to know what the purpose of the dot is for on the camshaft as well. In addition to that I want to know what the same marks mean on the distributor/intermediate shaft pulley, as I have currently aligned the crankshaft pulley with the dot and NOT the OT mark on the distributor/intermediate shaft, just for reference when the front bottom cover is removed those two pulleys are meant to align with the respective timing marks.

My OCD is just kicking in a little as to me it makes sense if I am to align the camshaft with the OT mark, then I should be using the OT mark on the distributor/intermediate pulley also. So if anyone can provide some insight into this it would be very much appreciated. If anyone has the official workshop manual which covers my car and spec and is able to provide some photos of what it says in the book that might be useful too! Don't worry I do intend to buy one, but money is a bit tight right now so am having to make do.