Skoda Favorit Pierburg Puzzle

[RicardoM]

faraj
The main problem is the new gasket. The components are not perfectly flat from factory. You must resurface them using sandpaper fixed on a flat surface. Make new softer cardboard gaskets (no package cardboard with holes!). I use 1-2 mm folder cardboard and as sealant I use 'liquid gasket' from Victor Reinz (petrol and heat resistant sealant). If you can find silicone rubber or Viton sheets (1-2 mm thickness) and make gaskets instead of cardboard and sealant... it will be perfect. I couldn't find.

 

Trust me, it is a verified solution on many Felicias. Don't torque hard the screws. It is a common mistake. Let the sealant cure for 20 minutes before assembly. Do NOT start the engine immediately. Let the sealant cure more overnight. It is possible the seal gets better after the engine gets hot and you drive 20 km. The more attention to details, the better. Be patient. Remember: vacuum leaks = total disaster. NO vacuum leaks = the perfect car.

 

PS

You don't have to quote my entire post to reply. Write directly the message.
 

Edited 17 February, 2016 by RicardoM

[faraj4]

thank you Ricardo for the great informations....but i have some questions plz: 

1- sandpaper should be soft or rough ?

2- can i use gasket maker liquid instead of 'liquid gasket' from Victor Reinz ??

3- do i have to put the sealant or gasket maker ( if i can use instead ) in touch with the manifold and the carburator ?

4- i dont have torque meter ... what can i do instead ???

5- do i have to put sealant on the gasket between carburator's upper and lower parts ?

6- for silicone rubber or viton sheets ,do i have to resurface the carburator base ?

7- do i have to resurface the plastic spacer too ? or just the steel base ??

[KenONeill]

Hints:-

1) For the flat surface, if you can source a piece of toughened glass (I used a glass shelf from an old refrigerator), you can attach the paper to this with double-sided tape.

4) Do you have a spring scale? I mean the sort that you hang the item to be weighed from. If so, then it's adequate for setting torques. Use it to pull on your spanner/socket wrench.

[RicardoM]

thank you Ricardo for the great informations....but i have some questions plz: 

1- sandpaper should be soft or rough ?

For the steel part you can start sanding on a grinder stone. You will see immediately how warped is the steel plate. When the plate is almost flat, switch to medium sandpaper (P80) then finish with finer sandpaper (P120). You don't need a mirror finish, just flat surface.

 

2- can i use gasket maker liquid instead of 'liquid gasket' from Victor Reinz ??

It is the same thing. Resistant to gasoline and high temperature (up to 300 C)

 

3- do i have to put the sealant or gasket maker ( if i can use instead ) in touch with the manifold and the carburator ?

Of course. Use the nozzle of the tube to make a 2 mm continuous bead. Do not spread the sealant!

 

4- i dont have torque meter ... what can i do instead ???

A torque wrench is nice to have around cars, but it can be expensive to buy for one job only. The alternative is to fully screw in the screws by hand (clean well the threads first!) then one full turn, then finally another half turn. Remember, even torque.

 

5- do i have to put sealant on the gasket between carburator's upper and lower parts ?

No. Vacuum gets formed only below throttle plate.

6- for silicone rubber or viton sheets ,do i have to resurface the carburator base ?

Normally no, but both the manifold and the base of the carburetor could be warped from heat cycles. I usually resurface only the intake manifold. Better check yourself both.

7- do i have to resurface the plastic spacer too ?

Yes. Check for equal thickness too.

In case you need more clarification, you can attach photos or share videos.

[faraj4]

thank you very much Ricardo , i think no more clarification is needed .

now i'm looking for silicon sheets .

my cousin told me that he can bring me a tube of liquid silicone that is heat resistant , is it right to use it or not ?( in case i couldn't find sheets )

[RicardoM]

Viton rubber sheet (1-2 mm thickness) -> EXCELLENT

Silicone rubber sheet (1-2 mm thickness) -> VERY GOOD

Victor Reinz gasket maker (fuel & heat resistant) -> GOOD

Red gasket maker (heat resistant) -> SATISFACTORY

[faraj4]

you mean i cannot use the liquid silicon ??? ok thank you a lot ... i'll tell you what happens with me ..

Edited 21 February, 2016 by faraj4

[RicardoM]

I don't know what you mean by "liquid silicon". If it is the red RTV silicone packaged in a red tube with a white nozzle, heat resistant only, and smelling like vinegar... you can use it but it is less effective because the fuel dissolves it. That is why it is the last one on my list.

 

[faraj4]

hi Ricardo 

i found this gray rtv silicone 

note : thinking about rubber , what about making gasket of internal wheels shown in the 3rd photo ???? 

Edited 22 February, 2016 by faraj4

[RicardoM]

You can use that gray RTV silicone.

 

About making gaskets from inner tyre rubber: forget about it! Don't even try. I tested for 3 months(!) various types of materials (cardboard, rubber, leather, etc. etc...). The only viable solutions are the ones described previously. Any other solution failed immediately or in maximum 3 days of driving. That lower carburetor gasket is the weak spot of Felicia on carburetor. The original gasket failed after 15 years (!). The new gaskets are a disaster.

[faraj4]

i can use the gray rtv silicone alone ? or with cardboard?

and if alone i should make a 2 mm continuous bead ?

Edited 23 February, 2016 by faraj4

[RicardoM]

• Resurface the steel plate.
• Resurface the black plastic spacer. Remember, equal thickness.
• Make a carboard gasket type A. Apply a continuous bead of gray RTV on both sides.
• Make two cardboard gaskets type B. Glue them (with Superglue or similar) on each side of the black plastic spacer. Apply a continuous bead of gray RTV on both sides.
• Let the RTV cure for 20 minutes.
• Place / align gasket A on the intake manifold.
• Place / align the steel plate on top
• Insert 4 screws and torque as instructed. Clean excess RTV from the hole of intake manifold.
• Place / align (the black spacer + gaskets B ) on top
• Insert 3 long screws through carburetor and align them trough holes
• Torque the screws as instructed.
• Let the RTV cure overnight
• Start the engine the next day. The gasket will seal best after a day of driving.
• Set the idle speed and the mixture for smooth idle.

 

Edited 23 February, 2016 by RicardoM

[faraj4]

Hi Ricardo

Here's what happened with me : I found that the vaccum pull down leaks , now I'm looking for a new one .

The good news that I found rienzosil from victor rienz , the bad news that I couldn't find a new vaccum pull down till now, i tried to deassemble the vaccum pull down , but it can't be repaired .

Im in real trouble now .

Thank you for your help , I'll let you know if something new happened.

Edited 3 March, 2016 by faraj4

[RicardoM]

Im in real trouble now

No, you're not. The solution is simple. Remove old pulldown unit (PDU) and thermo-time valve (TTV) completely. Plug the vacuum line (see photo). That's it.

 

 

The PDU is useful only in cold weather (below 0 C) to avoid total closure of the choke flap which is a no-start condition from air starvation. Similarly, the TTV is useful only in very cold weather (below -20 C).

 

I removed the PDU and the TTV from my carburetor too, mostly because new units are very poor quality (aka designed to fail). Moreover, we don't have too much cold weather in here anyway.

 

You can find a good article about repairing the PDU here. It is in Russian but that shouldn't be a problem. Some people machined a metallic housing for the PDU.

 

Edited 4 March, 2016 by RicardoM

[Breezy_Pete]

^ I like it. (Both the simplification/deletion where not needed, and the Russian ingenuity).

 

There's a tiny possibility that I might have a working 2e3 pulldown unit somewhere on a spare 2e3.  I know I had one at one time, but may have 'tidied up' too much and thrown it out.  I will try to look for it over the weekend.

[faraj4]

hi Ricardo 

i did everything as you told me to do ( resurfacing , using rienzosil , removing PDU , blocking the hose with a ball , removing TTV ) ... but i still have the same problem which is : i turn the co mixture screw all the way in and the engine stays running . i have black smoke from the exhaust . 

what should i do now ???? do i have to check the servo pipe ??? or anything else ???

thank you for your help

[RicardoM]

The best thing I can think of is to use an improvised smoke machine to check for vacuum leaks. See video below. In essence you need a source of low pressure compressed air (hand pump, foot pump, barbeque hand-cranked fan, nebulizer compressor, etc.), hoses, a jar, couplings, a rubber glove, tape, a source of thick smoke (cardboard, smoking pellets for bees, etc.) and a bright flashlight to see the smoke. The only acceptable leak is around the bushings of the 1st stage throttle plate axle.

 

 

Only after you are 100% sure there is no vacuum leak, you can look for other things as described below.

 

One other thing. The black smoke is indicative of a rich mixture condition. Carburettors are very sensitive to fuel level in the float chamber. Did you replace the float needle with another one from a repair kit?

 

When the mixture screw is screwed in all the way, the idle circuit is blocked. The engine should stall from fuel starvation at idle. If perfect vacuum is not achieved, that raises the fuel level in the float chamber and we say the carburettor is flooding. Basically the entire functionality of the carburettor is messed up. Fuel is not controlled, air is not controlled due to leaks and the engine runs like $hit. I've seen engines that can't be shut off, I've seen engines that revv by themselves to 4,000 rpm, and all kind of weird stuff. But when vacuum is restored, the engine runs as good as an injection one.

 

I've uploaded for you the best repair manual for Pierburg 2E3 (Jikov LEKR 28-30). Read it and see if any setting is not as specified.

http://www5.zippyshare.com/v/4bkTdv8f/file.html

[RicardoM]

There's a tiny possibility that I might have a working 2e3 pulldown unit somewhere on a spare 2e3.

A spare one? That is a goody. What else do you have in your Aladin cave?

[faraj4]

I checked for vacuum leaks , fixed them all , same problem with mixture screw, black smoke increesed .

I didn't replace the float needle , but I don't know if the former owner did ?

Can i measure fuel level in float chamber without removing the carburator out?

One more notice : when i push the brake pedal in , or out , rpm raise from 800 to 1100 then goes back to 800 , is that normal ?

[RicardoM]

I didn't replace the float needle , but I don't know if the former owner did ?

Neither do I.

Can i measure fuel level in float chamber without removing the carburator out?

No.

One more notice : when i push the brake pedal in , or out , rpm raise from 800 to 1100 then goes back to 800 , is that normal ?

Yes. But only if you push the pedal repeatedly in rapid succession.

The plastic tube that goes from the intake manifold to brake booster has a one-way valve (see photo). Check it. Maybe the brake booster itself is defective. I would like to help more, I am confident I could repair the carburettor or any related problem, but you are too far

Let's try another approach. Take pictures of the engine from all angles. Also detail pictures around carburettor and brake booster. Even better, make a video showing 3 stages: start of the engine, running at idle and revving it a few times. Show the exhaust too. The idea is to see as much as possible to understand what is going on.

 

Important questions:

• what year and what mileage has your car?
• since you bought the car, did the engine ever run well?

Edited 9 March, 2016 by RicardoM

[faraj4]

Hi Ricardo

I have doubt about enrichment valve , looking at the photo you've posted before , i see 5 holes in the valve and 3 holes in the gasket . my valve has only 3 holes and the gasket also 3 holes . why is that ?

And the holes should be placed up or down ? For the valve and the gasket .

[RicardoM]

Do you have a Pierburg 2E3 or a Jikov 28-30 LEKR carburettor?

Please reply to my previous 2 questions too.

Edited 9 March, 2016 by RicardoM

[faraj4]

my car is 1998 , about 200,000 km .

it's written on the side of the Carb ( jikov , made in checkoslovakia ) 

my car ran well only one time and for about one week , it happened when i fitted the hoses in right positions ( they were fitted wrong )

today i tried rotating the distributer : black smoke got lesser , but i didnt have luck with the mixture screw .

note : when i bought the car about one year ago , a mechanic changed piston rings , they were faulty 

Edited 10 March, 2016 by faraj4

[RicardoM]

So the car ran well only for about one week since you bought the car one year ago. My question is: then what happened?

 

Did the engine start running bad:

1. suddenly, without any intervention?
2. gradually?
3. when you tried to clean the carburettor by removing it?

If you want me to help you all the way, I need to know every related details. Including possible carburettor modifications made by the previous owner (fuel jets, float, float needle, enrichment valve, etc.)

 

The enrichment valve / gasket should look like in the photos below.

 

 

 

 

If the gasket or the valve are defective, fuel will leak into intake manifold (see photos, fig. A=good valve/gasket, fig. B=failed valve/gasket) resulting in rough idle, rich mixture impossible to correct from the mixture screw. So if you are 100% sure there are no vacuum leaks, I would replace the enrichment valve and gasket with new ones.

 

 

[faraj4]

hi Ricardo ..

finally i found where the problem is : mixture screw , i had to change it two months ago , because it was broken as you see in the photo , i brought another one , and discovered yesterday that it doesn't block the mixture when it's screwed the whole way in , you can see the difference between the two screws in the photo , now i'll look for new screw that fit in my carburator , i wish to find one ,

thank you for your help