DougT wrote:Pierburgs were fitted to Cologne V6's so that does make sense. But they still have a needle valve. If the needle valve is not sealing properly due to wear or corrosion then the float chamber will overflow and leak somewhere.
If you still get leakage at the carb then it is likely to be the needle valve.
Doug
Doing some work on the carb now as it seems to be a cause of issues. Perhaps I should start a new thread on it?
Anyhow, the carb is a Pierburg/Solex EEIT 38 as far as I was able to find out. It keeps getting dirty at the front and sides as fuel escapes. Fuel valve and floater has been changed. The old floater was broken, I was not able to get an original spare part, so I had to adopt my own floater. Took some time to adjust the fuel level in the chamber, but I believe now it should be fine.
I have two issues, first the fuel leak and second synchronizing air/fuel mixture. And finally a question about vacuum advance in between.
Fuel leak:
Here you can see the dirt I am talking about. It's wet after driving. I got it cleaned recently and since have driven some 500km.
The seal shown in the green box is not original. I had it custom made. I opened the top cover after the engine was running a while. The area in the green box was soaked in fuel.
Blue circle: there's fuel in this opening. When engine is running, some air bubbles slowly build up in it.
Purple box: fuel seems to accumulate here. Not sure where it's coming from.
Vacuum
Red circle: the tube goes to the distributor. The last mechanic who did some work on my carb decided it was better to put a metal ball into the tube. So the distributor is not getting any vacuum. He said it sounded better that way. Any thoughts on this
Synchronizing/air fuel mixture
This may be related to the fuel leak. But first let me show you my throttle valves. As you can see, the right one opens further than the left one. Is this a big issue?
[img=http://abload.de/thumb/img_20180703_115639e2em6.jpg]
Next, my spark plugs.
Hope this image makes clear which plug I'm addressing.
1,3,4,5,6 looked like this. I believe these are fine are they not?
But 2 looked like this.
Am right to believe that throttle valve I (right one looking from the radiator) feeds cylinder 1,2,3 and throttle valve II feeds 4,5,6?
When engine is cold, soot particles are shooting out of the exhaust. More so on the right one which connects to cylinders 1,2,3. Once the engine gets hotter, the exhaust gets cleaner.
I set my idle to around 900rpm. I say around because it is not running smooth. Variation is +/-100 rpm. After driving a bit and then idling, the engine sounds like as if it was accelerating for a few seconds and then suddenly slowing down again, dropping rpm. As if there was some sort of load against it keeping it from 'spinning freely'. When rpm drops, there is some sort of banging noise coming out of the right exhaust (cylinders 1,2,3) and the exhaust gas flow interrupts for a second.
Last observation, when I remove the top cover of the carb while idling, rpm immediately jump up to 1400. Engine runs a lot smoother then, no weird noises. Is this normal? Or may this be related to the fuel leak?
Air/fuel mixture screws are quite far out on both sides.
Last but not least, please keep in mind that I am currently at high altitude (above 8000ft/3000mt)