A question about the gap of spark plugs, i use Champion RC89PYC and supposed to have an 0.8mm gap

 

 

Let's say it's wrong for example 0,9 or 1mm, can that cause any kind of problems at cold start but not after the car gets heated after few minutes?

A small wrong gap like this is noticeable while driving at higher rpm or not?

If all the plugs have the same (small incorrect) gap it's better than if the gaps vary on one or more of the plugs.

 

Even though the plugs come pre-gapped it is best to check the gap as soon as you get them and return any that are wrong to the seller.

 

If your car has been mapped then I do not know but very much doubt, if it is all programming, that the mapper/tuner would have widened the gap, you would have to ask to be sure.

 

Possibly a platinum plug might foul up more, you would have to check this as your car is not standard - I assume you are not LPG too.

 

Even the old-farts that have the same model of "classic" (over-priced and over-valued) car as mine prefer to run on NGK than Champion.

 

Not that my car would run well on platinum or iridium but I prefer to use standard copper NGK and change them every two years as they are so in-expensive and so easy to get at.

 

Edited 6 February, 20224 yr by nta16

3 minutes ago, nta16 said:

Possibly a platinum plug might foul up more, you would have to check this as your car is not standard - I assume you are not LPG too.

 

Skoda gives the Champion RC89PYC as ''factory spark plugs" for Felicia.

An NGK Copper never worked for me, i have a specific thread for those.

https://www.briskoda.net/forums/topic/491830-ngk-bkur5et-10-your-opinion-about-them/

No LPG.

57 minutes ago, D.FYLAKTOS said:

Skoda gives the Champion RC89PYC as ''factory spark plugs" for Felicia.

That would probably be as a commercial contract at the time, plus of course 21 years have passed and your car is not as factory.

 

 

57 minutes ago, D.FYLAKTOS said:

An NGK Copper never worked for me,

But at that time did you not have your problems with coolant and mapping - if you still have them I would try putting the BKUR5ET-10 back in now you are sorted.  However it depends on what plugs were in when the mapping was last corrected, this is the thing with tuning if you make changes then you may have to change the tuning which is why it is best to tune to allow for the wide ranges of circumstances for driving on roads throughout the year rather than what looks best at any given time.

 

I am not a big fan of looking at spark plug colourings, there are lots of variables and they need to be pulled at the relevant point otherwise subsequent use and actions alter the colouring.

 

If you wanted you could perhaps got to NGK with BKR5EIX-11.  I assume (always dangerous) you engine is in the AMG, AMH, AMJ group.

 

1 hour ago, nta16 said:

That would probably be as a commercial contract at the time, plus of course 21 years have passed and your car is not as factory.

 

I assume (always dangerous) you engine is in the AMG, AMH, AMJ group.

 

The parts e-shops give those Champion as an option and to be honest i forgot to ask the programmer if i need a different type of spark plugs.

I have the SKODA FELICIA II (6U1) 1.3 with AMH motor code.

 

20 hours ago, D.FYLAKTOS said:

Let's say it's wrong for example 0,9 or 1mm, can that cause any kind of problems at cold start but not after the car gets heated after few minutes?

A small wrong gap like this is noticeable while driving at higher rpm or not?

 

I still wonder.

2 hours ago, D.FYLAKTOS said:

I still wonder.

As a simplified generalised answer, if the gap is too wide then yes you could get a misfire at higher revs. - (Champion) Consequences of Incorrect Spark Plug Gap - https://www.championautoparts.com/Technical/Tech-Tips/Spark-Plug-Gap-Tip.html

 

0.8mm to 1.0 is a big gap difference (0.0345" to 0.0394").

 

To sound like a stuck needle, you must also consider your car is remapped so a small gap increase depending on applicability of plug may possibly be good, or might not.

 

56 minutes ago, nta16 said:

you must also consider your car is remapped so a small gap increase depending on applicability of plug may possibly be good, or might not.

 

It's a risk that i can not take it by myself, i have to ask the programmer, i don't want to make experiments with sparks plugs.

 

As for the change of brand it's a mess, here is an example from an Uk store:

https://www.sparkplugs.co.uk/compatible-parts/spark-glow-ignition/spark-plug-100151?ktype=11193&vtype=P

and as for cross-reference then it's a huge mess:

https://www.sparkplug-crossreference.com/convert/CHAMP_PN/RC89PYC

 

😲

20 minutes ago, D.FYLAKTOS said:

It's a risk that i can not take it by myself, i have to ask the programmer, i don't want to make experiments with sparks plugs.

In that case you need the plug type that was in when the remapping was done.

 

 

23 minutes ago, D.FYLAKTOS said:

As for the change of brand it's a mess, here is an example from an Uk store:

It's not a change of brand if you had NGK BKUR5ET-10 at time of remapping.

 

Different stores will offer a different range of plugs, based on their databases and the fact that the model of plug could be superseded by the manufacturers of the plugs.  It is like tyres and other parts if a large vehicle manufacturer wants a very specific part to be made it will be because of volume.  It may be, and I do not want to shatter anyone's believe or marque loyalty but often a tweak to a part like tyres or plugs is needed to compensate for little glitches of design and manufacture, er sorry I mean, improvements in design and manufacture of the vehicles.

 

As for databases they are unreliable as they are merged and errors are copied and multiply with more merging, copying and copying in substitute plugs full cross reference listings.  The computers and internet have accelerated and exasperated the problems as no one checks previous lists and just accepts them.  You would need to go back to when your engine was first used in your model and see what each spark plug manufacture had listed for your model and year and even then accept that some may be more suitable or better than others.  Sometimes you can find PDFs of parts manufacturers' or supplies' catalogues from that time which will list the part numbers, but they may have changed the part number or superseded the part.  Then you must also consider the plug would be for what was considered suitable at that time for a new factory standard car running at that time with the petrol, oils, ect. of that time.  It is a good base starting point for a factory standard car that may or may not be bettered now given today's circumstances and how the car is now.

 

You may find  you have to accept a reasonable level for what you expect in a spark plug  for your car as your real aim is for a level of precision that is simply not available or realistic in plug selection and certainly not without computer program tuning perhaps with rolling road use and/or real world road use over a reasonable period of time to cover all types of your use of your car.

 

Chances are standard plug or one move away from it will be as far as you can get, then there could be slight variance for better or not so good from different manufacturers.

 

33 minutes ago, nta16 said:

You would need to go back to when your engine was first used in your model and see what each spark plug manufacture had listed for your model and year and even then accept that some may be more suitable or better than others.

 

Skoda manual says Champion RC89PYC, the same is on Haynes manual that's why i hesitate to make any change (the NGK didn't work, some Iridium didn't work) but nor me or the mechanic measure the gap ever.

Just plug and play and there is a rumour that those which have that protective cap are already been adjusted from the factory.

 

 

 

I can imagine copper plugs would be the best suited, but as I put before when you were testing the BKUR5ET-10 is that not at the same time as your coolant was too thick and before the last remapping, if so that could have had some influence on the results.

 

The NGK plugs at least are factory set, and any three/four prong I imagine, to whatever is on the packaging but if they have been dropped or messed with (parts returned by customers) then perhaps they might be damaged or gap reduced.  Have you never taken a part out of its packaging to realise that you were not the first to do so.  Best to check all parts as soon as you get them so you have time to get replacements if needed rather than halfway through the job when the shops are shut.

 

How about less is more - Denso K16PR-U or if you must IK16TT K16TT- https://www.denso-am.co.uk/products/automotive-aftermarket/ignition/spark-plugs/

 

My car does not have the fancy electronics yours has but I found going from the very basic NGK to the recommended Champion or NGK or superior NGK made no odds to the actual running that I could tell.  I now buy the recommended NGK or the basic NGK if I see them at a good price.  (I set them 0.003" (0.076mm) wider as that was best setting for my car when tested on the rolling road (dyno)).

 

Edited 16 February, 20224 yr by nta16
0.003"

9 hours ago, nta16 said:

I can imagine copper plugs would be the best suited, but as I put before when you were testing the BKUR5ET-10 is that not at the same time as your coolant was too thick and before the last remapping, if so that could have had some influence on the results.

How about less is more - Denso K16PR-U or if you must IK16TT

 

https://www.denso-am.co.uk/e-catalogue/

 

K16TT and K16PR-U are Nickel

IK16TT is Iridium (which means NO WAY)

No Copper spark plugs by Denso for me.

1 hour ago, D.FYLAKTOS said:

K16TT and K16PR-U are Nickel

Nickel is fine they are copper otherwise - "Copper spark plugs have bodies made of copper with center electrodes comprised of nickel alloy."

 

"The majority of spark plugs feature a copper-core center electrode. Copper is an excellent conductor of electricity – better than any other type of material used in spark plugs – and also transfers heat faster. However, copper is soft and has a low melting point so it is always covered with a nickel alloy to protect it." - Champion Guide to spark plug materials - https://www.championautoparts.com/Parts-Matter/automotive-repair-and-maintenance/Spark-Plug-Materials.html 

 

 

1 hour ago, D.FYLAKTOS said:

IK16TT is Iridium (which means NO WAY)

Sorry that was a typo (well copy&paste) I meant K16TT.

 

“Also, there is a myth that the fine-wire precious metal plugs should not be gapped. That is a false statement. You should always double-check the gap using a wire-style gapping tool. We do not recommend using the ‘coin’ style gapping tool because it can damage the fine wire tip.”

 

I bought from an e-store a feeler blade plus a coin gap tool, i want to measure the gap from my spark plugs so any suspicion will let go.

Still waiting for the courier to come.

 

At cold start in the morning or at noon the needle rises normally and stays a little bit at 1100 rpm returning to 800 rpm

At night inside the parking lot refuses to let the 1100 rpm for few minutes and then returns to 800 rpm.

Why at night only? I don't know and this makes me nervous.

Personally I dislike the coin style as I was given a top pocket pen clip style Mac Tools linear bar version and I find it difficult to see and read (shiny chrome finish too) I prefer individual feeler gauge blades.  It was only last year I got a full set as I was fed up of having to use two blades combined to get the correct thickness on my previous set.  I like my bent wire feeler gauge but it was metric and the car is in imperial.

 

 

On 07/02/2022 at 18:00, D.FYLAKTOS said:

At night inside the parking lot refuses to let the 1100 rpm for few minutes and then returns to 800 rpm.

Why at night only? I don't know and this makes me nervous.

I thought you had sorted this.  Are you running the car at this time with an electric load of lights, heater blower, (wash/wiper, radio, etc.)? 

Edited 16 February, 20224 yr by nta16
spelling

13 hours ago, nta16 said:

I thought you had sorted this.  Are you running the car at this time with an

electric load of lights, heater blower, (wash/wiper, radio, etc.)? 

 

Till 100 Km on the odometer everything seems to go well but latter things start changing.

My ''late" cold start is at night when i am leaving from work to home, the car is 5 floors below earth on a parking garage (of course the air is different than outside but the temperature is one click higher) and always is different than the cold start at morning or noon when the car is parked outside on the road (fresh air but sometimes lower temperature).

 

So last night i have made a test, nothing else On (radio, heater etc), start the car with no revving and counting the time till the needle drops to 800 rpm which is the idle level and the temperature will rise.

Here are the results, the engine went at 1100 rpm and when dropped to the idle the timer wrote:

 

 

I don't think this is normal.

Does seem strange, what about doing the same but driving straight off whilst timing and see if the drop takes as long.

 

Or if you can reverse the morning/noon and evening starts so that you start the car 5 floors down at morning/noon and your late night start with the car outside.

 

Or both morning/noon and late night starts outside to see if it might be an environment and/or time thing, so also perhaps a morning/noon and late night start underground.

 

What might have changed during or at that 100km?

 

How are your TC-6 figures on this longer higher idle compare to before?

 

There is no possibility a Felicia 1300cc that has a fuel consumption of 5.3-6.8 ltr/ 100 Km in national road and sport driving then burn in mild city driving 12-13 ltr/ 100 Km. 

It does not make sense for a car to want 3.5 minutes idle at 1100 rpm while 6 hours before it needs almost half a minute.

These two are world phenomenon!

I am not disagreeing, I thought you wanted to find out why, I was just making suggestions to what might be available to you to try..

 

The 12-13 ltr/ 100 Km is a new figure you have just presented.

 

Previously you had IIRC a broken air inlet flap, over-rich coolant and a remapping but I can not remember your ltr/100km figures being anywhere near that high.

 

Unless you are saying different the issue seems to start from late night starting  5 floors down which in itself does not seem to make a lot of sense.

 

Do you remember the chap who had to push start his car only in the morning, yet I and others thought his starter motor seemed fine yet he discovered it was just the cold morning start the motor could not cope with, if he had not kept investigating the starter motor it would have remained dismissed.

 

9 hours ago, nta16 said:

Unless you are saying different the issue seems to start from late night starting  5 floors down which in itself does not seem to make a lot of sense.

 

I have exactly the same issue for months now, it's not last night.

My night cold start (at the parking garage) is far more different that the morning/noon cold start.

 

https://i.imgur.com/6liowjL.mp4

 

This was few months ago and nothing changed till today. I have made a repair to the 4 cables of the coolant sensor plug (2 were bending too much, one was a naked spot plus one was a little bit loose).

I can not compromise with the idea that a 1300cc car burns in city the same fuel as a Mitsubishi Lancer Evolution VIII.

Well these are the only things I can think of and they are repeats from before and stuff you will not like or agree with but as I put I am not a mechanic or expert in anything just a distance observer of the information you have given.

 

The cables to the coolant sensor may be significant especially the one with a bare patch and other with loose connection, you will find out from the results of the repairs if this is so, and all being well this might be the end of it.

 

If not, I would confirm the TC-6 readings, reverse the environments and times of the starts, try to get scan tool readings if possible, perhaps consider that there is an error in some programming, consider if other sensors or the wiring or connections (as with coolant sensor) are faulty including at computer.

 

What was different about the first 100km to not have this problem, could the coolant refill work have moved anything (wires, cables, hoses, tubes, flaps, mechanical, etc.) that temporarily sorted the problem to later resettled back to causing this problem.

 

Any computer resets (battery disconnection perhaps) that cleared the problem for a while for it to return.

 

If some starts are different to others and from that there is increased consumption it would suggest to me that some sensor or programming (or possibly even something mechanical or other electrical) is not moving away, or causing the effect, from a cold start setting to running setting quick enough and/or fully - in my car it would be something like a choke jet sticking on when it should be released.

 

In the 3:42 minutes the idle is high from the cold start, I would look under the bonnet and after the normal time for the idle to drop has passed I would wiggle wires, connections, cables, mechanicals to see if it causes the idle to then instantly drop.

 

I have little idea from the start but have totally run out of ideas now, sorry.

 

Edited 9 February, 20224 yr by nta16

I returned from the electrician at 9:45, parked my car and 13:30 i start it to go to work and guess what? The needle was on 1100 rpm for few minutes before drops to 800 ( i was on the move, i didn't use the timer).

The car was not cooled down, the 2nd cool start of the day is always like this, i have changed the coolant sensor yesterday with a spare that i had so it's not his fault.

The fuel consumption now is 12,2 ltr/ 100 km which is unexeptable for this car.

2 hours ago, D.FYLAKTOS said:

i have changed the coolant sensor yesterday with a spare that i had so it's not his fault.

Fair enough but what about the wiring and connections to this, and the wiring and connections to the other sensors, what sensors do you have on your car?

 

Then there's the other stuff previously mentioned.

 

When you are getting this poor fuel economy are you are to tell if the car is lacking in power, or does the city driving prevent this.

 

Whilst you are getting poor fuel economy have you noticed anything different coming out of the exhaust.

 

As I understand it your TC-6 measures off the car's sensors (?), if so can you disconnect it from the sensors so they are running by themselves without any connection to any part of the TC-6 system and seal and protect any connections then drive the car normally for a few days with it disconnected.  I know the TC-6 does not control anything only monitors but wiring or connection problems can throw up weird issues.

 

Also have you confirmed that you are actually using more fuel other than the TC-6 readings and idle remaining at 1100 for minutes?

 

4 hours ago, nta16 said:

The cables to the coolant sensor may be significant especially the one with a bare patch and other with loose connection, you will find out from the results of the repairs if this is so, and all being well this might be the end of it.

Obviously if you are fitting a new plug connector all of the previous posts contents can wait until you have done this and confirmed the results of the replacement.  Good luck, I hope it is this, often can be.

 

Edited 9 February, 20224 yr by nta16

9 minutes ago, nta16 said:

As I understand it your TC-6 measures off the car's sensors (?)

 TC-6 has one fuel sensor and another one on the rpm gauge. He uses the factory floater sensor. It reads rpm and the fuel that sprayed and then makes calculations. I can see the Instant fuel consumption, the Average, the Total, the Remaining kilometres.

TC-6 is not a scanner tool,can not adjust anything or interfere to correct anytging, it's just reads and shows to you.

 

The coolant sensors were based the VW specifications, no overhearing problems, also the thermostat works fine.

 

The "guilty" is something that has the power to make the ECU to make the fuel mixture rich at low-middle rpm but to perform very good at higher rpm (mountain road, national road).

 

 

2 minutes ago, nta16 said:

Obviously if you are fitting a new plug connector all

 Ordered a new from Aliexpress, will take a month to come.

The factory cables repaired, in few hours at night cold start will see if these were the "guilty".