Are from my Felicia 1.3, i had them for about 5200 Km inside town only which means traffic, no hi-way or boulevard over 100km speed etc.

2 photos are with flash.

Can you tell me your opinion about the combustion?
 

Edited 28 March, 20215 yr by D.FYLAKTOS

You need a bit colder plugs judging by the discoloration of the threads and it runs okay maybe a tad rich but safe non the less

14 hours ago, Thefeliciahacker said:

You need a bit colder plugs judging by the discoloration of the threads and it runs okay maybe a tad rich but safe non the less

Those 2 spark plugs are not the same, NGK are Cooper and Champion are Platinum.

I saw a increase in gasoline consumption and in cold starts the car was a little bit ''wild" as back in the old days when we forgot the manual choke valve open.

 

I asked for a check on the Fuel Pressure Control Valve (OE Number: 047 133 035) and told me that the pressure was 2,7 bar and stable

The Haynes manual says it's 2,5 bar and i wonder who's right?

 

 

 

Workshop manuals says around 2.5 bar. More important is, whether presure rises to around 3bar, when vacuum tube to the regulator is disconnected?

Well, I'd say the car is running rich.

 

Also, I'm dubious about the benefits of multi-electrode and/or precious metal spark plugs in an engine design this old.

1 hour ago, KenONeill said:

Also, I'm dubious about the benefits of multi-electrode...

 

Multi-electrode plugs are prescribed by Skoda...

Edited 2 April, 20215 yr by Papez

 

8 hours ago, Papez said:

Workshop manuals says around 2.5 bar. More important is, whether presure rises to around 3bar, when vacuum tube to the regulator is disconnected?

 

Yes, 3.1 was when the vacum tube was off

With the plastic cover plus the tube from the filter removed (the throttle was ''naked'') shown 2.7

Is that 0,2 bar responsible for the increase of the fuel consumption?

MAP,Lamda sensor,coolant sensor and air-filter are OK.

 

As for the videos and charts with spark plus there are dozens at least for 2 decades, the issue here is to find WHY those spark plus are like this and IF those NGK Cooper plus are appropriate for an old design motor.

I  don't see anything wrong with the spark plugs while driving only in a city traffic. It is the worst life for a car.

Only if the spark plugs look the same after a long highway drive, I would be worried.

I use Platinum spark plugs for 20 years in my car and they never were in such a condition, i don't see the reason why the mechanic put Copper.

 

My first concern is the pressure of the fuel, few days ago i read 2.5 bar in a product description, at Haynes i read also 2.5 and latter the gauge shown 2.7 bar.

Which pressure is the proper one?

IF the pressure is not right then no matter the spark plug the combustion wouldn't be good.

Some guys say ''don't care about the Fuel Pressure Control Valve, if is damaged the car won't even start or will idle so bad that you will turn off the engine by yourself'' but i cannot rely on this.

22 hours ago, D.FYLAKTOS said:

Platinum spark plugs for 20 years in my car and they never were in such a condition, i don't see the reason why the mechanic put Copper

Yes, but you had the best available heat grade, and the correct mixture and timing. Most plug faults trace to wrong plug grade, or miss-set mixture and/or ignition timing, not of choice of electrode materials.

39 minutes ago, KenONeill said:

 not of choice of electrode materials.

But suddenly with those spark plugs i had fuel consumption problem plus i don't like so much the way they look.

 

Trying to find if there is a problem with my fuel pressure valve if found this an a Czech forum,

https://www.skoda-techweb.cz/forum/viewtopic.php?p=616313&sid=06d9a9fbec84d64e8d397cead42110d5#p616313

 

Here is the translation:

Today I connected a new pressure gauge measuring the current value of the pressure between the hose and the bar with the regulator connected. When the key is turned, there is 3.1 bar almost immediately, after switching off the pump relay, the pressure drops to 2.9 bar. With the engine running and the vacuum disconnected, there is 3.1bar, after connecting the vacuum 2.5bar. So, in my opinion, the measurement confirmed that the pressure with the engine stopped is the same as the pressure with the engine running. Video from the measurement with the engine running here:

 

https://vimeo.com/379263375

 

 

 

Right pressure is 3bar relative to the intake air pressure. Disconnecting vacuum tube or measuring with engine off simulates intake air pressure being same as atmospheric pressure, which is why fuel pressure rises to 3bar.

44 minutes ago, Papez said:

Right pressure is 3bar relative to the intake air pressure. Disconnecting vacuum tube or measuring with engine off simulates intake air pressure being same as atmospheric pressure, which is why fuel pressure rises to 3bar.

 

 

 

Here is another relative video.

 

My first concern is the pressure of the fuel in my car if is good, after seeing those videos i feel reassured because i though i had a problem.

Next i have the ''Gas pump" test to see if the fuel consumption is less than with those NGK on.