Idling issues and more on 2.0 8v carb golf mk2

[NeelsSanders]

Hi guys

Let me start by apologizing for the long post. I just want to give as much info and a bit of background as possible to get help from you guys. Also most of the problems listed has already been searched for on the web but with no luck as to an exact die or mostly not the exact problem.

So about a month or two ago I've got a VW Golf MK2 with a 2.0 8v carbed motor and 5spd manual transmission. It also has an A.C. but no power steering (which I've came to realize would be a beneficial upgrade in the future). So when I got the car I was told that the engine had been overhauled not to long ago. I was told that the reason for letting the car go was because it used to much fuel for the purposes it was used for and the guy wanted to get something more fuel efficient. When i took the car for a test drive i could smell that it was running way to rich. It didn't bother me as I thought it would be an easy fix and may also sort out the fuel problem. And that's the beginning of where my troubles began. Also I don't think the guy who overhauled the engine did a good job. First of all the oil that was in it was very thin and pitch black like it's very old. Now this could be due to the rich condition resulting in fuel mixed with the oil as it did have a gassy smell. Also after a week of driving the bottom fan belt broke and you could see it was because of age meaning that it wasn't replaced. I then replaced both fan belts as the one for the alternator also looked very old. This makes me wonder about the timing belt also. And then there is a noisy lifter in the engine also with could mean it wasn't properly adjusted. All this could also mean that the engine may not have been overhauled to start with. And if it was overhauled, what was the cause for such a job to begin with?

So after getting the car, I didnt have the correct size battery to put in it. And since the car starts and ends with the battery I thought that mentioning the fact that I have a little bit of a smaller sized battery in it, would be a good idea. Now let me start with the following. When cranking the car, sometimes the started sounds like it's struggling to turn (ie. Turning slowly). But after switching of the ignition and trying again it would turn over. Sometimes it takes two to three tries before the starter would turn the engine. But if it doesn't turn over on the second or third try or even sometimes after the first try, the battery would be flat. I've noticed that when recharging the battery to full with a charger, it would crank quite a few times or keep power longer than if it was kicked start and recharged by the alternator. Giving me the idea that it isn't being charged the same amount by the alternator than by the battery charger. Now could all this be caused by the fact that the battery is to small? Or maybe the battery is on its way out? Also does the fact that the charger do a better job mean that my alternator is failing? Or is the slow turns of the starter due to something else taking away the proper amount of current needed for it to turn or is the starter failing? I've noticed that there is about 4 wires connecting to the terminal on the starter? Is this a problem?

Now getting to the car running rich. I thought this would be an easy fix but turned out that till this day in still struggling. The car has a Keihin carb on it. At me start by saying also that it has a throttle positioning valve ( or what ever the thing is called that mount on the firewall with to hose connections on top and one at the bottom and two electrical wires coming out from the bottom). Now this thing as well as the vacuum line coming out of the passenger side from the firewall which I assume is for the ac, isn't connected. The one from the a.c. doesn't bother me that much as the a.c. doesn't work at this moment due to a broken pipe near the a.c. radiator. So coming back, I bought a carb kit and took the carb apart and cleaned it thoroughly and rebuild it using the an exploded view for the Keihin carb. One thing u did notice on there is that on the image it has a secondary idle air bleed as to where mine it blocked of by some kind of a small ball in the place where the secondary idle air bleed jet goes on the image. But next to the primary idle air bleed there's a big flat flathead screw. If screwed out it look like some kind of a metal rod on it and using a small flat in the hole there's another jet. Question is what is this jet for and why is it blocked of by this big screw? Now after putting everything back together and mounted the carb on too of a new gasket, I thought all would be good as the carb was quite dirty. After first start and some adjustment, the carb ran lean no matter what u did. But the smell from the exhaust still smelled like gas although all other checks stated it to be lean. Took it apart again just to find out the primary air bleed jet was to large that came with the kit. Also noted that the main butterfly was drilled as would be done if a bigger cam was fitted. Got a new butterfly and replaced it also. Now the car runs rich again though not as much as the first time. Even when changing air bleed jet with the larger size that came with the kit it would run lean again. The AF mixture screw looks like it's only for the idle circuit and this is the only mixture screw on there. But this screw makes little to no difference in Thaler rpms or mixture. Only if turned in about 1/2 turn from seat engine will sputter and surge. Same thing if turned 1/2 then from all the way out. But in between nothing much would change. No matter how finely turning, rpms won't become even and engine keeps being rich. Although accelerating seems fine with no hesitation or stumble all through out rpm range. Only sometimes has a little bog when suddenly pressing accelerator after 20+ seconds of idling. Although bog disappears when trying again right after that. Like I said only happens when engine idles without acceleration for 20+ seconds. Another thing is when rpms drops from high or when dropped suddenly, it would drop below set idle but returns within5 seconds or so to set idling although sometimes higher. The higher the rpms were upon releasing accelerator the more the drop and sometimes engine surges. This doesn't happen as often when car is just being revved from idle, but happens mostly when driving and pressing clutch with food of accelerator, like when coming to a stop. Then again there is a bit of a lean power loss when the second stage opens. Now I've noticed that someone grinded the second stage stop plate in order for the second stage to start working sooner. At the time it would open when primary is about 10% open or at about 1500 rpms. This is very soon and could be the possible cause of the lean power loss. How could I fix this lean condition by leaving second stage to open sooner as I would actually like it this way. Perhaps decrease secondary air bleed? So with all this problems, I've already checked the float setting, vacuum leaks, replaced plugs and air filter, adjusted ignition timing (though only by feel and sound as I can't find my timing light. It's been set at where engine idle is most steady and fast), checked fuel supply and filter, checked vacuum connections. All these seem fine. But I have a rough or unsteady idle, a rich condition, a dip in revs or surge when coming of throttle, a bog after some idling upon sudden acceleration,a lean power loss on second stage and engine requires more throttle to pull away ( not meaning it has to be revved, only the throttle must be pressed quite deep when releasing clutch). I've also noticed that one of the spark plugs has a small chip gone at the end but could be because of the lean condition it had. Also the one plug lead came loose at the end a bit but isn't exposed.

So once again sorry for the long post. I've listed as much details as possible and will reply with some other details if you guys ask.

Thanks in advance for any help guys. I do have a few other problems but would ask for help on that after this issues has been resolved for now. Otherwise post would become much longer.

[NeelsSanders]

Another thin I've forgot to mention is that the brakes isn't very responsive. It's not hard. But it doesn't have quite a lot of braking power for the amount of peddle being pressed. It's almost like it's to soft instead of hard. It becomes worse after a long or extended period of driving without braking, and also when suddenly braking from a high speed. That when its the worst actually as pedal is almost instantly being pressed to quite deep but car doesn't stop instantly or wheels doesn't even lock. And it feels like the harder I press the brakes the softer it becomes and the deeper it sinks. Could this perhaps mean the booster is faulty causing a vacuum leak inside the booster maybe. And be the cause of the rough idle and lean condition and why I cab find any vacuum leaks. I've also noticed that when going over a speed bump with foot on the brake, as soon as car takes the shock it will loose braking power and pedal will sink a bit further away. Also I noticed that there's only one brake line coming out of the cylinder which splitsinto 4 pipes for a small block. Two goes to each of the front wheels and two goes into a small piston like thing that's attached to a spring at the left rear wheel. And then looks like it has a piston inside such is being pressed by the piece attached to the spring. Then out of this is the two lines going to the rear brakes. What is this thing and what is it used for. Also is the fact that there only one brake line coming from cylinder correct? And should the brakes be soft and become worse from higher speeds or when hitting a speed bump? Is the booster the solution to all my idling and carb related problems?

[Ryandevraj]

Hello, sad to hear about your situation. I have also been having hell with a golf 1 that i bought which the previous owner stated the engine was redone and all is good. The swinging the engine to start problem sounds liking a battery on its way out or a timing problem i.e belt timing and ignition timing way off, that would also cause a rich condition and hard start. A rough idle could be the carb but also as you stated with the brakes it could be a vacuum leak on the intake manifold to brake booster. If your car is idling and you press the brakes does the car start hunting for revs?if so time to check brake booster and vacuum line to it. hope that helps

[VAG Fan]

A few thoughts.

Rather than guessing, measure your alternator. A rested but charged battery should read about 12.6-12.8 V. Once the engine runs, the alternator should put out about 13.8-14.1 V. There should be very little voltage difference between the alternator and the battery. Under load (lights, defroster, fan etc.) the alternator should still put out 13.5 V or more. Again, check both the alternator and the battery voltage.

Regarding the mixture: if you don't know what was done to the carburetor, it will be really difficult to get it back into spec. The adjustment screw is only for idle mixture, as you correctly noted. The air-fuel ratio while driving is determined by fuel jets, air correction jets and auxiliary mechanisms, e.g. push-rod for partial load enrichment, acceleration pump, second stage actuator, etc.. Most of these items are either fixed or have been factory set. They can be modified or adjusted to some extent, but you really have to use a dyno and/or oxygen sensor to get it right. And you have to know where you started from, so that you can return to basics if a mod doesn't work. Not knowing what was previously done to the carb and the rest of the engine (camshaft?), you're really shooting in the dark. One approach would be to get the carb back to factory spec, but you need a repair manual and spec sheet for that. The other option is to replace the carb completely.

I'm no tuner, but this is what I would say based on my experience: you've bought someone else's headache.

[NeelsSanders]

Thanks for the replies guys.

Today I've replaced the pipe going to the brake booster as well as all the vacuum lines. But idle issue is still there. Late this afternoon a friend of mine called to come help him with a Weber fitment on his mk1. In return for the help he gave me his carb which is the same Keihin model. The carb came of his 1.8 running so I don't see there being a carb issue after fitting it on my car. Fitted the carb late this afternoon and didn't have time to make some adjustments. So upon first start engine wouldn't run without choke being pulled out a bit but not to far as to the point where it will push against throttle on the carb. This told me that it was running a bit lean. After driving of the first thing I've noticed was a huge difference in overall power. But seeing that the old carb had a mod done to the secondary stage to open earlier and was connected to a stronger vacuum signal than original port, this doesn't quite concern me to much for now. After getting home I've made a quick adjustment to idle screw and mixture screw. Got it to idle at least possible idle without stalling and smoothest setting on the mixture. It idles at around 1050 rpms and going any lower would cause the car to stall as it's already kind of hunting for revs at this point. Stewing the mixture screw in or out by even a milimeter from where it's now would make idling worse. The 40km drive home went really good even with less power than old carb. No fuel smells what's or ever and also fuel gauge almost didn't even move a bit. Going me more reason that this carb is fine. As I said it worked 100% on my friend car. So with all vacuum hoses replaced and completely sealed, what could still cause this erratic and jumpy rough idle.could there be a leak on the gasket under the carb. Although spraying carb cleaner or quick start on it didn't make a difference in rpms. But that can also be because the old carb was completely gone. Will check tomorrow again. I tried to adjust distributor timing again by ear and feel today, tough still with old carb, and it's at the best smooth and high idle position it can be. I know this isn't the way to do it but until I find my timing light this position can't be that far off. And even though it was adjusted with old carb, being at this position should also be more beneficial with this new second hand carb shouldn't it. Didn't check can to crank timing yet though, as you guys said that could also be old not knowing what the previous owner did to it. Just to answer your question Ryandevraj, when applying brakes even before replacing vacuum hoses, there were no change in rpms. That's what also put me off the idea that it was booster related. Only asked because I may be looking for booster related problems the wrong way. And to answer VAG fan, I did do a voltage test and after driving battery measures 12.7v and at idle alternator reads 13.7v. Tough after one crank of slow turning starter and no success on second try, battery voltage would drop to 12.2v and this without any thing on only the ignition being in start position for about 5 seconds with slow turning starter. I did mention a scratching or grinding kind of sound at alebator today. To my experience this usually mean that alternator is on its way out. But looking at the voltages it seems to be putting out power quite fine. But could all this related problems maybe mean that alternator does charge but has times while driving where it wouldn't function. Causing battery to be charged but at times be drained while driving because of the alternator? Also, could all this idling and starting and charging issues maybe be the result of an ignition coil being on its way. Or perhaps that small thing in the driver side rain tray going to the distributor. Can't seem to remember what it's called right now. Could one of these to thing be the solution to all of my problems in facing.

Thanks again for the help guys

[VAG Fan]

[Edit: it sounds as though the replacement Keihin that your friend gave you, is a much better option.]

Re. the idle:
Is the idle cut-off solenoid connected properly, including the earth connection of the carb to the cylinder head or valve cover? The solenoid must click audibly when the ignition is switched on and off.

Re. the voltage:
You can always route an extension lead (e.g. some flex wire) from the battery to the inside of the car and connect your voltmeter there. Then you can observe the voltage while driving. But from what you wrote above, it sounds as though the battery is simply old and starting to fail. Have you checked the electrolyte level? If one of the cells is low, get some (proper) distilled water and top it up. Don't fill it completely, but cover the plates.

P.S.: please try to group your ideas into paragraphs. It makes for easier reading.