Felicia 1.3 carburetor tuning

[PaulWalls]

Hi skoda fans I have problems with my carburetor it is sucking too much gas and it is affecting my economy even though gas is very cheap in my country (1 US galon = 1.49 USD or 2.55 liters per dollar!). I removed the carb and cleaned it, then I noticed that the second stage didn't work, it was stuck, I proceeded to repair it, when I mounted the carb again, it wasn't any improvement. Every night I think to rebuild it, but I am afraid to seriously damage it, I will try to take photos and post them on this forum. Thanks in advance for your valuable comments.

[KenONeill]

Paul, from your earlier description of the spark plug noses (covered in dry black sooty deposits) I'm pretty sure that your car's running rich.

The standard checks in this case are:-

1. carburettor mixture
   
2. carburettor float level
   
3. choke operation
   
4. air filter blocked.
   

In your case, if the car was normally kept at a significantly higher altitude, the mixture could be badly mis-set.

The first thing to do is check the air filter. Depending on make the filter paper should be either yellow/orange or white. If it's a dirty blackish colour get a new one.

Next, if the car was kept at a higher altitude (no-one else can check this for you), we want to reset the mixture, but let's confirm that this is the problem before trying to fix it!

[PaulWalls]

I have already changed the air filter not with the original part but with something that just fit in there instead. But I think it shouldn't affect that much, should it?

When the mechanic rebuilt the engine and we mounted the carburetor back, he couldn't regulate the idle rpm, the fuel mixture adjusting screw had no effect on the carburetor and the engine just went off if I didn't keep my foot on the gas pedal.

The mechanic performed an "adaptation" of some kind using a piece of wire, and since that, I have been running that way, but it is driving me mad, because 1) the engine is extremely weak and 2) it is consuming too much fuel.

I wish I could take some photos so you can have a more realistic look and we can surely find a solution. I am quite convinced you are more capable and honest than many bloody mechanics! I would rather expend my money on spare parts. (-by the way- are very cheap).

[adurer]

You have below the link to the most comprehensive service manual for Pierburg 2E3 carburettors.

http://www.share-byte.net/d8f3EO

There are lots of photos and illustrations inside, a troubleshooting table, etc.

I repair almost weekly a carburettor having similar symptoms.

Unless you made big assembly mistakes, you have a vacuum leak below carburetor where that flange attaches to intake manifold. Best way to test that is to run the engine at idle then to screw IN all the way the mixture screw. If engine doesn't stop, here's your problem.

Use a new flange and check for flat surfaces. Even new gaskets are warped. Carburettor base gets warped too!

Take photos and show us that wire.

[PaulWalls]

Yes, Adurer yes, in fact the problem might be what you just posted, There is a big vacuum leak somewhere, that ugly rubber flange that joints the carburetor and the intake manifold, I heard, the original flange is metalic, not this ugly one that I have right now, that could be part -or the whole problem! I love this forum! By the way, thanks for the information about PIERBURG 2E3, I have like 10 different manuals! some in English and some in German. Now is cristal clear for me I have to buy a new original metalic flange ASAP! Thanks again! (I have put my wife in stand-by position). I really want to get over this problem.

[PaulWalls]

It should be read "THROTTLE PLATE SCREW" instead of "mixture adjusting screw", this is where the mechanic set his piece of wire.

[adurer]

Rubber flanges they make now in China are crap. Stay away from them!

The new flange design is better. But you have to be sure they are FLAT. Very, very important.

I had to use sandpaper on both metal plate and plastic plate. Do this on a flat surface. Take your time, this operation makes all the difference between a rough working engine and a smooth powerful economical one.

Another critical point: do NOT torque bolts too much!! Book says 8 Nm.

One last thing about the wire that 'mechanic' put in there. It is probably to keep the throttle cable in place, because he lost the little C clamp.

Edited 22 January, 2013 by adurer

[KenONeill]

I agree with almost everything adurer has said, except that Paul's comments in post #3 have me wondering if the thread for the mixture screw has been stripped. This usually happens when some @$$hole tries to keep tuning a carburettor leaner and leaner.

[Wright Bro's]

I had a vacuum leak when I had the old pierburg fitted so bought that new flange kit adurer showed and it fixed the problem... If you're still not sure if it does have a vacuum leak or not then squirt some "easy start" around the flange/gasket while it's idling and see if the revs increase. Also have you seen this thread:

http://www.briskoda.net/forums/topic/238327-diy-smoke-machine-for-vacuum-leaks/

[PaulWalls]

I really appreciate all of your help and your time. I am patiently awaiting for my month check to buy that new metalic flange that I hope will make the whole difference, and if not, I won't blame you, I will keep on trying. A special thanks to ADURER.

[adurer]

Dude, how much is that flange?? We buy it in here with 10 US dollars.

[PaulWalls]

I have finally bought the "carburetor support metal" for $13.00 and it looks exactly like the photo.

The metalic gasket has two sides one with the inscription VIKA and a code number, this part looks to me absolutely flat and the other side is dented with tiny holes, this part is completely flat too, and my question at this point is:

<do I still have to sand both sides or which side?> <What number of sandpaper do you recommend?>

Regarding the other black gasket which looks to me made of mica and with a kind of paper-like sides, it looks flat too, and if I sand it, I'm afraid I could damage the very thin paper-like layer. Do I have to sand it too?

What is the secuence of assembling? What comes first?

There is a paper gasket, where should it be placed? Should I use a gasket sealer?

[adurer]

Don't sand anything yet.

Installation order is: cardboard gasket, metal plate with 4 Allen screws, black plastic spacer, carburettor with 3 long Allen screws.

Degrease metallic mating surfaces with carburettor cleaner.

Torque all Allen screws at 8 Nm, not more.

[PaulWalls]

Thanks again for your time and patience. I have two questions:

1) I don't have a "torquemeter" or any similar tool in order to calculate 8Nm, I guess I wil have to trust my err hand?, having in mind not to tighten too much the screws.

2) regarding the "metalic mating surfaces" you mean all the metalic parts that are in contact with the manifold? Could you please clarify this point a little further?

Thanks!

[adurer]

1) Before installing anything: clean very well the threads of bolts and holes. I used carburettor cleaner. Apply a very thin film of grease on bolt threads. Tighten bolts by hand all the way. We do that to verify threads are good. Do that for the 4 short bolts and 4 holes in manifold and also for the 3 long bolts and 3 holes in metal plate.

2) Clean manifold surface with carburettor cleaner. Wipe with a clean rag.

3) Put cardboard gasket. Align holes.

4) Clean metal plate both sides (see point 2)

5) Put metal plate over cardboard gasket. Align holes.

6) Insert and tighten 4 bolts by hand all the way in a cross pattern (see photo below) Check that metal plate is seated properly all around..

7) Using an Allen key, tighten the bolts 1 turn at a time in a cross pattern. You'll feel when to stop if you think "I don't want to break a bolt in the manifold hole."

8) Put plastic spacer over metallic plate. Align holes.

9) Clean carburettor base (see point 2)

10) Insert 3 long bolts through carburettor and install carburettor over plastic gasket. Screw by hand the 3 bolts all the way. Check that carburettor is seated properly all around.

11) Using an Allen key, tighten the bolts half turn at a time in order (see photo below). You'll feel when to stop if you think "I don't want to strip the thread of the bolts."

12) Job done. Enjoy. Beer brake.

Photo is not from a car repaired by me. I work much cleaner.

Edited 27 January, 2013 by adurer

[PaulWalls]

Excellent Adurer! (like always), very clear explanation, thanks! I finally got a camera to take photos. I will post them -hopefully tomorrow. Thanks again!

[adurer]

Mr. Albrecht Durer uploaded a tutorial on uploading and sharing photos.

http://www.briskoda.net/forums/topic/263657-how-to-upload-photos-videos-then-share-them/

[PaulWalls]

http://yfrog.com/ghc...torsupportset1j

[adurer]

Very good photos.

Keep in mind that you only have 1 (one) MByte TOTAL space available for attachments...

[PaulWalls]

Well folks I proceeded to change the carburetor base. It took me around 3 hours! But finally everything went ok, well almost everything.

After doing my job, I was very excited but the engine didn't start! I had to literally suck gasoline with my mouth to fill that small plastic vase that conects the inlet of the carb. After 45 minutes of checking and re-checking everything the engine finally started!

I sincerely expected a radical change but I guess my expectations were too high. The engine is still weak and I am not satisfied. What's the next step?

[PaulWalls]

I have started a new topic regarding a stubborn gearbox oil leak.

http://www.briskoda.net/forums/topic/263751-felicia-13-heavy-gearbox-oil-leak/

[PaulWalls]

Adurer please have a look at the wire inserted in the carburetor.

http://img802.imageshack.us/img802/7595/wireinsertedincarbureto.jpg

[PaulWalls]

Adurer please have a look at the wire inserted in the carburetor.

http://img94.imageshack.us/img94/7595/wireinsertedincarbureto.jpg

[PaulWalls]

Wire inside de carburetor.

http://img802.imageshack.us/img802/7523/wireinsertedincarburetoe.jpg

http://img856.imageshack.us/img856/7595/wireinsertedincarbureto.jpg

http://img829.imageshack.us/img829/7595/wireinsertedincarbureto.jpg

http://img15.imageshack.us/img15/7595/wireinsertedincarbureto.jpg

http://img805.imageshack.us/img805/6075/wireinsertedincarburato.jpg

http://img69.imageshack.us/img69/6075/wireinsertedincarburato.jpg

http://img35.imageshack.us/img35/6075/wireinsertedincarburato.jpg

[adurer]

I gave you the link to the best carburettor manual there is. You have EVERYTHING in there.

But you have to READ it. You'll find out that's not a wire, but the end of a spring.

Remember that tuning a carburetor is not the easiest thing for an amateur.

Think of carburettor as the engine computer. You need skill, experience and tools.

If it took you 3 hours to mount that gasket and 45 minutes to start the car...

PS

Do not take photos so close to objects. Your camera doesn't focus properly in macro mode.

Edited 29 January, 2013 by adurer