A Belgian member needs help for a little problem (Civic Vx, D15Z1 engine).

[SVOboy]

At that RPM could the lag perhaps be the VTEC kicking in?

[GasSavers_TomO]

Do you have NGK ZFR4F-11 spark plugs readily available? If you do, swap those into your car and see if the hesitation is reduced then.

I'll have to watch the video to see the response time of the LAF as I cannot watch Youtube videos at work.

[VEI]

Originally Posted by SVOboy

At that RPM could the lag perhaps be the VTEC kicking in?

At that RPM, yes it would be possible but I don?t think so.

Look this video :
http://fr.youtube.com/watch?v=IiTz8jA7fWM

(It is a climb). I push slowly on the pedal but the car doesn't accelerate, there are some small hesitations. Suddenly, with the same constant pressure, the car accelerates faster.
And no VTEC at that RPM (12 valves).

Do you have NGK ZFR4F-11 spark plugs readily available? If you do, swap those into your car and see if the hesitation is reduced then.

I don?t know, this is normaly not the good spark plugs for Civic VEi. I always had ZFR5F-11 and no problem before.
I think that the spark will be better with ZFR4F-11, perhaps less hesitations, but the heat will be too high (bad for the engine).




And sorry for my bad English, I hope you understand what I want to say lol

[GasSavers_TomO]

Originally Posted by VEI

At that RPM, yes it would be possible but I don?t think so.

Look this video :
http://fr.youtube.com/watch?v=IiTz8jA7fWM

(It is a climb). I push slowly on the pedal but the car doesn't accelerate, there are some small hesitations. Suddenly, with the same constant pressure, the car accelerates faster.
And no VTEC at that RPM (12 valves).

That is the motor coming out of "Lean Burn" mode....looked pretty normal and a decent response time of the LAF to me.

Originally Posted by VEI

I don?t know, this is normally not the good spark plugs for Civic VEi. I always had ZFR5F-11 and no problem before.
I think that the spark will be better with ZFR4F-11, perhaps less hesitations, but the heat will be too high (bad for the engine).

Does your motor have a sticker on the top timing belt cover that shows the recommended plugs?
Like this (picture from my d15z1):

The lean burn really needs a hot plug to ignite the lean mixture well.

Originally Posted by VEI

And sorry for my bad English, I hope you understand what I want to say lol

Your English is very good! And your use of Youtube is a great help as well. Keep it up.

[VEI]

Originally Posted by TomO

That is the motor coming out of "Lean Burn" mode....looked pretty normal and a decent response time of the LAF to me.

I don't understand why I have 1.3V in acceleration (low RPM, low load) and 1.1v in deceleration.
Normaly there are no injection in deceleration...

I think 1.3v is perhaps too much. I push the accelerator, so more air intake, but the car doesn't accelerate (like no more injection). I don't know if it's normal during "lean burn".

When I have bought my car, i haven't this problem.


-------------------------------

What is the english word for "air/fuel"? Is it "mixture"?

This can be rich or (???) What is the correct word : "poor" or "lean"?

Originally Posted by TomO

Does your motor have a sticker on the top timing belt cover that shows the recommended plugs?

Yes.

[GasSavers_TomO]

Originally Posted by VEI

I don't understand why I have 1.3V in acceleration (low RPM, low load) and 1.1v in deceleration.
Normaly there are no injection in deceleration...

Upon looking over my lean burn thread, 1.1V on deceleration is a bit strange. One possibility maybe be a leaking injector, or having a high electrical load.

Originally Posted by VEI

I think 1.3v is perhaps too much. I push the accelerator, so more air intake, but the car doesn't accelerate (like no more injection). I don't know if it's normal during "lean burn".

When I have bought my car, i haven't this problem.

1.3V is normal "rich" for acceleration. I have seen it as high as 1.4V.

Are your driving habits the same as when you first had the car? How many kilometers were on the car when you bought it?

Originally Posted by VEI

What is the english word for "air/fuel"? Is it "mixture"?

This can be rich or (???) What is the correct word : "poor" or "lean"?

In English, we use the phrase "air/fuel mixture" or "air/fuel ratio". It can be rich, stoich, or lean.

Originally Posted by VEI

Yes.

That is interesting that it suggests the ZFR5F-11 plugs on the sticker.

Could you please post the numbers on the side of your ECU for us as well? I am interested to see if the ECU version is different than the US model.

Thanks!

[GasSavers_bobski]

Originally Posted by VEI

I think that the spark will be better with ZFR4F-11, perhaps less hesitations, but the heat will be too high (bad for the engine).

As I understand it, that middle number is the heat value of the spark plug. Hotter plugs have a deeper well around the center electrode, reducing heat dissipation to the cylinder head which results in a hotter center electrode.
A hotter plug shouldn't cause the engine to overheat, though it's possible it could cause pinging. What's the typical octane rating of gasoline in Belgium?

[VEI]

Originally Posted by TomO

Are your driving habits the same as when you first had the car? How many kilometers were on the car when you bought it?

66000km

Now : more highway.
But I doesn't have problems on highway because the engine is running at 4000RPM (short gearbox now).

Originally Posted by TomO

Could you please post the numbers on the side of your ECU for us as well? I am interested to see if the ECU version is different than the US model.

The Honda reference for my car is : 37820-P07-G02. Is it this number that you want?

As I understand it, that middle number is the heat value of the spark plug. Hotter plugs have a deeper well around the center electrode, reducing heat dissipation to the cylinder head which results in a hotter center electrode.
A hotter plug shouldn't cause the engine to overheat, though it's possible it could cause pinging.

Yes, that's right.
Hotter sparkplugs : can perforate a piston.
Colder sparkplugs : fouling of the spark plug, bad ignition.

What's the typical octane rating of gasoline in Belgium?

95 or 98.
For my car : 95.
What is the ocatne rating in US?


My sparkplugs, last month :

That seems me too white.
Before, they were more gray.

[garyhgaryh]

plugs look good! It's a lean burn engine remember.

[GasSavers_bobski]

Originally Posted by VEI

Hotter sparkplugs : can perforate a piston.

I kinda doubt that, but I don't blame you for being cautious. You would have to be running lean under high load to get the piston hot enough to melt. Detonation can break the ringlands off the piston or occationally punch a hole in it, but that generally only happens with cars running aftermarket forced-induction (supercharger, turbocharger, nitrous) systems.

Originally Posted by VEI

95 or 98.
For my car : 95.
What is the ocatne rating in US?

87, 89 and 91 are most common, but as high as 95 can be found at some stations.