P38A Modulation

wammers · Jul 25, 2020

Wazzajnr said:
I may be wrong here, but I think what Keith is trying to say is that the "stable" idle temperature on two different vehicles could easily be different by, let's say, 5 degrees and that could lead to a detectable difference in modulation which has potential to fool some people into thinking they have a problem when maybe they don't.
It would be interesting to see several different vehicles modulation against actual temperature to see just how much difference it really makes.

The stable idle temp on a vehicle with the viscous fan and shroud removed and one with the viscous fan and shroud fitted will certainly differ. It's not the temp of the engine but the temp of the fuel that is the problem.

Wazzajnr · Jul 25, 2020

wammers said:
The stable idle temp on a vehicle with the viscous fan and shroud removed and one with the viscous fan and shroud fitted will certainly differ. It's not the temp of the engine but the temp of the fuel that is the problem.

It will differ between vehicles with the shroud and viscous fan fitted.
By how much, I have no idea but it will vary.
If investigation shows that it is only by a degree or so then you are absolutely right that it doesn't matter and can be forgotten about.
If however it is found that across 10 {for example} vehicles that the temperature can vary by 5 or more degrees then Keith's point makes a lot of sense.

Tenebreaux · Jul 25, 2020

Grrrrrr said:
Who else has a diesel and a Nanocom? Lets get some data and compare. A sample of 2 isn't worth ****.

Next time I do a decent long run I will take a trace of the temperature afterwards and see how stable the temp is.

Happy to have a look tomorrow. Where exactly in the nano menu am I reading from?

wammers · Jul 25, 2020

Wazzajnr said:
It will differ between vehicles with the shroud and viscous fan fitted.
By how much, I have no idea but it will vary.
If investigation shows that it is only by a degree or so then you are absolutely right that it doesn't matter and can be forgotten about.
If however it is found that across 10 {for example} vehicles that the temperature can vary by 5 or more degrees then Keith's point makes a lot of sense.

It's the temperature of the fuel in the injection pump that matters. With cold fuel and the engine running at 750 RPM the internal pump will make more pressure than it does with warm fuel. Needing more modulation. The warmer the fuel gets the less modulation is required. That is why modulation check is done at idle with engine up to temp. Without a viscous and shroud no air is being blown over the engine or drawn through the rad. So the temps can never be really be normal and stable. It will always be higher without a viscous and shroud. Until his aircon fans kick in there is no cooling effect at all. So the engine will run hotter at idle than it should be doing. Giving a false modulation reading.

Wazzajnr · Jul 25, 2020

wammers said:
It's the temperature of the fuel in the injection pump that matters. With cold fuel and the engine running at 750 RPM the internal pump will make more pressure than it does with warm fuel. Needing more modulation. The warmer the fuel gets the less modulation is required. That is why modulation check is done at idle with engine up to temp. Without a viscous and shroud no air is being blown over the engine or drawn through the rad. So the temps can never be really be normal and stable. It will always be higher without a viscous and shroud. Until his aircon fans kick in there is no cooling effect at all. So the engine will run hotter at idle than it should be doing. Giving a false modulation reading.

Yes yes yes, I get all that but what is normal in deg c.
This will be different from car to car.
Also, the temp of the fuel in the pump will vary with ambient temp irrespective of there being a viscous fan fitted or not.

wammers · Jul 25, 2020

Wazzajnr said:
Yes yes yes, I get all that but what is normal in deg c.
This will be different from car to car.
Also, the temp of the fuel in the pump will vary with ambient temp irrespective of there being a viscous fan fitted or not.

As said earlier ring BBS and argue with them those are their instructions for checking modulation. But I rather think they are not referring to a car that has had it's viscous fan and shroud removed.

Wazzajnr · Jul 25, 2020

I don't really care anyway, I was just trying to word it differently so you might understand what is being asked but you clearly either don't know or don't want to tell.

RangeRoller dt · Jul 25, 2020

When my FIP was really bad I removed the shroud thinking more heat would disperse but it just got hotter/worse, increases fan efficiency enough that made a noticeable difference without it

wammers · Jul 26, 2020

Wazzajnr said:
I don't really care anyway, I was just trying to word it differently so you might understand what is being asked but you clearly either don't know or don't want to tell.

I know what's being asked, it is a daft question. The answer is as always, when the engine is up to it's full idle temp at 750 RPM.

Grrrrrr · Jul 26, 2020

Tenebreaux said:
Happy to have a look tomorrow. Where exactly in the nano menu am I reading from?

Put an SD card in. Start the car. Plug Nanocom in. Go to EDC and then fuelling. Press save. It will start recording after you enter a filename Wait until the needle is at 12 o'clock and then wait another couple of minutes. Press save again. Come out of fuelling and go into General. Do a trace there for a minute or so then shut the Nanocom down and then stop the car.

Put SD card in computer. Zip it and then upload it here!

wammers · Jul 26, 2020

Grrrrrr said:
Put an SD card in. Start the car. Plug Nanocom in. Go to EDC and then fuelling. Press save. It will start recording after you enter a filename Wait until the needle is at 12 o'clock and then wait another couple of minutes. Press save again. Come out of fuelling and go into General. Do a trace there for a minute or so then shut the Nanocom down and then stop the car.

Put SD card in computer. Zip it and then upload it here!

Then remove your viscous fan and shroud and do it again.

Wazzajnr · Jul 26, 2020

wammers said:
I know what's being asked, it is a daft question. The answer is as always, when the engine is up to it's full idle temp at 750 RPM.

So, can you put it into figures?
And cam you accept that it will vary from vehicle to vehicle irrespective of whether the viscous and shroud are fitted?

wammers · Jul 26, 2020

Wazzajnr said:
So, can you put it into figures?
And cam you accept that it will vary from vehicle to vehicle irrespective of whether the viscous and shroud are fitted?

It may vary slightly from vehicle to vehicle but it will vary a lot from standard if there is no fan and shroud. Why is you are always trying to stir the shit?

Wazzajnr · Jul 26, 2020

wammers said:
It may vary slightly from vehicle to vehicle but it will vary a lot from standard if there is no fan and shroud. Why is you are always trying to stir the shit?

I'm not trying to stir anything, I'm just trying to highlight that he has a point if the idle temperature varies between vehicles.
You've got a bee in your bonnet about his electric fan mod and cant/won't see past it.
All you needed to say was "I don't know what the stable idle temperature is" and I wouldn't have said another word because, as stated earlier, I really don't give a rats arse.
You just have a pathological inability to admit when you don't know something.
There's no shame in not knowing you know!

wammers · Jul 26, 2020

Wazzajnr said:
I'm not trying to stir anything, I'm just trying to highlight that he has a point if the idle temperature varies between vehicles.
You've got a bee in your bonnet about his electric fan mod and cant/won't see past it.
All you needed to say was "I don't know what the stable idle temperature is" and I wouldn't have said another word because, as stated earlier, I really don't give a rats arse.
You just have a pathological inability to admit when you don't know something.
There's no shame in not knowing you know!

No i have no bee in my bonnet about his electric fans. He asked a question of me he got an answer he didn't like. End of story.. If you don't care STFU.

wammers · Jul 26, 2020

Wazzajnr said:
So, can you put it into figures?
And cam you accept that it will vary from vehicle to vehicle irrespective of whether the viscous and shroud are fitted?

What sort of idiot are you?

Wazzajnr · Jul 26, 2020

wammers said:
What sort of idiot are you?

As usual, when you get called out you just get rude and abusive.
What a wonderful chap you are!
I'm out.

wammers · Jul 26, 2020

Wazzajnr said:
As usual, when you get called out you just get rude and abusive.
What a wonderful chap you are!
I'm out.

I have not been called out. You are talking nonsense yet again. There is nothing to be called out about. You know nothing listen and you might learn. You do talk some rubbish.

RangeRoller dt · Jul 26, 2020

Me and Oakey just watch and wait.
You learn so much even if after the debate the thread never happened.
Does rattle the newbies if its their threads, ask me how I know ...
By the time they settled down I knew how to fix a RR

wammers · Jul 26, 2020

RangeRoller dt said:
Me and Oakey just watch and wait.
You learn so much even if after the debate the thread never happened.
Does rattle the newbies if its their threads, ask me how I know ...
By the time they settled down I knew how to fix a RR

Sometimes i cannot believe some of the clueless tossers on here.

P38A Modulation

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